user520: Is there any point to casual mining anymore? I recently discovered bitcoin and was wondering if there was any point to running mining software on my laptop while I work on essays or other non-computationally intensive task. I tried looking around, but answers seem conflicted on if casual mining is possible.
I mean will I get any bitcoins from it, not is it profitable per unit cost of electricity. Will I get anything in a reasonable timeframe or is that now a thing of the past? By anything I mean, the silly 0.1BTC I see stuff put up for on http://forbitcoin.com and such, not hundreds of dollars to supplement my income.

user323: If your costs are minimal (for example, you don't pay for electricity), yes, there is some point in casual mining. You will have to mine in a pool (for example http://www.btcguild.com/) and don't have high expectations, but yes, you can get some coins over some time. If you care about how much will it cost you to generate those coins, you might want to consider buying the coins at https://mtgox.com/ .
If you want to know how much you can get in a reasonable timeframe, check out a bitcoin calculator, for example http://tpbitcalc.appspot.com/ .

user5: Mining in your work/home computer has some side effects, namely:

Heat - could damage your hardware if you don't handle it properly
Noise
Slowdowns - if you use your computer while you mine you should reduce the miner's load 
Power consumption - if you don't pay for electricity this may not be an issue

So I would say that there is a point in casual mining as long as your earnings compensate for these disadvantages. It is really up to you to decide if you want to stress your hardware to earn a few coins.    
Speaking of a more concrete scenario, casual miners usually fall into two categories:

You have a good GPU for mining in your PC - a recent medium/high end ATI card.
You don't have a good GPU so you want to mine with your CPU/low end GPU.

Check this question to find out where do you stand. If you have a good GPU, you might get around 8 bitcoins per month at current difficulty. If you don't, you will probably not earn more than 1 or 2 coins per month.
My personal opinion is that if you fit into the first category, you could give it a shot. If not, I wouldn't do it just for a few dollars (and I do not recommend mining with your CPU at all).
As a final note, bear in mind that these numbers are always changing: new hardware is coming out all the time and new miners are joining while others are leaving. This influences the amount of bitcoins you will earn with your hardware so be sure to check an updated hardware list for your calculations.

user108: TLDR: Rough estimate of electricity cost needed to produce one bitcoin on a laptop with 5 Mhash/s equals to 61 dollar, and would take 339 days with current difficulty.
A standard laptop CPU provides around 2-8 Mhash/sec and consumes 25 to 75 watts, which on average gives us 1 Mhash/sec per 10 watts of power.
An ATI 5870 video card, which has one the best efficiency/cost ratios, mines at about 400 Mhash/sec and consumes about 216 watts. Which gives us about 2 Mhash/sec per 1 watt of power. In other words mining with ATI video card about 20 times more cost effective then mining with CPU.
According to pi.uk.com/bitcoin, mining with ATI video cards at 1000 Mhash/sec will cost 650 watts or 9.75 cents (15 cent per kilowatt hour), and the operation profit margin would be 19.07%. Therefore I doubt it would be cost effective to mine on laptop considering that power consumption changes dramatically from computing intensive task. 
You can get better estimate yourself by using Bitcoin mining profitability calculator and Electricity Prices by State.

520: <p>Is there any point to casual mining anymore? I recently discovered bitcoin and was wondering if there was any point to running mining software on my laptop while I work on essays or other non-computationally intensive task. I tried looking around, but answers seem conflicted on if casual mining is possible.</p>

<p>I mean will I get any bitcoins from it, not is it profitable per unit cost of electricity. Will I get anything in a reasonable timeframe or is that now a thing of the past? By anything I mean, the silly 0.1BTC I see stuff put up for on <a href="http://forbitcoin.com">http://forbitcoin.com</a> and such, not hundreds of dollars to supplement my income.</p>
 323: <p>If your costs are minimal (for example, you don't pay for electricity), yes, there is some point in casual mining. You will have to mine in a pool (for example <a href="http://www.btcguild.com/" rel="nofollow">http://www.btcguild.com/</a>) and don't have high expectations, but yes, you can get some coins over some time. If you care about how much will it cost you to generate those coins, you might want to consider buying the coins at <a href="https://mtgox.com/" rel="nofollow">https://mtgox.com/</a> .</p>

<p>If you want to know how much you can get in a reasonable timeframe, check out a bitcoin calculator, for example <a href="http://tpbitcalc.appspot.com/" rel="nofollow">http://tpbitcalc.appspot.com/</a> .</p>
 5: <p>Mining in your work/home computer has some side effects, namely:</p>

<ul>
<li>Heat - could damage your hardware if you don't handle it properly</li>
<li>Noise</li>
<li>Slowdowns - if you use your computer while you mine you should reduce the miner's load </li>
<li>Power consumption - if you don't pay for electricity this may not be an issue</li>
</ul>

<p>So I would say that there is a point in casual mining as long as your earnings compensate for these disadvantages. It is really up to you to decide if you want to stress your hardware to earn a few coins.    </p>

<p>Speaking of a more concrete scenario, casual miners usually fall into two categories:</p>

<ul>
<li>You have a good GPU for mining in your PC - a recent medium/high end ATI card.</li>
<li>You don't have a good GPU so you want to mine with your CPU/low end GPU.</li>
</ul>

<p>Check <a href="https://bitcoin.stackexchange.com/questions/118/how-much-bitcoin-will-i-mine-right-now-with-hardware-x">this question</a> to find out where do you stand. If you have a good GPU, you might get around 8 bitcoins per month at current difficulty. If you don't, you will probably not earn more than 1 or 2 coins per month.
My personal opinion is that if you fit into the first category, you could give it a shot. If not, I wouldn't do it just for a few dollars (and I do not recommend <a href="https://bitcoin.stackexchange.com/questions/59/is-cpu-mining-even-worth-it">mining with your CPU</a> at all).</p>

<p>As a final note, bear in mind that these numbers are always changing: new hardware is coming out all the time and new miners are joining while others are leaving. This influences the amount of bitcoins you will earn with your hardware so be sure to check an <a href="https://en.bitcoin.it/wiki/Mining_hardware_comparison" rel="noreferrer">updated hardware list</a> for your calculations.</p>
 108: <p>TLDR: Rough estimate of electricity cost needed to produce one bitcoin on a laptop with 5 Mhash/s equals to 61 dollar, and would take 339 days with current difficulty.</p>

<p>A standard laptop CPU provides around <a href="https://bitcointalk.org/index.php?topic=1628.0" rel="nofollow">2-8 Mhash/sec</a> and consumes 25 to 75 watts, which on average gives us 1 Mhash/sec per 10 watts of power.</p>

<p>An ATI 5870 video card, which has one the best efficiency/cost ratios, mines at about <a href="https://en.bitcoin.it/wiki/Mining_hardware_comparison" rel="nofollow">400 Mhash/sec</a> and consumes about 216 watts. Which gives us about 2 Mhash/sec per 1 watt of power. In other words mining with ATI video card about 20 times more cost effective then mining with CPU.</p>

<p>According to <a href="http://pi.uk.com/bitcoin" rel="nofollow">pi.uk.com/bitcoin</a>, mining with ATI video cards at 1000 Mhash/sec will cost 650 watts or 9.75 cents (15 cent per kilowatt hour), and the operation profit margin would be 19.07%. Therefore I doubt it would be cost effective to mine on laptop considering that power consumption changes dramatically from computing intensive task. </p>

<p>You can get better estimate yourself by using <a href="http://bitcoinx.com/profit/" rel="nofollow">Bitcoin mining profitability calculator</a> and <a href="http://www.electricchoice.com/electricity-prices-by-state.php" rel="nofollow">Electricity Prices by State</a>.</p>
