user31419: I really like the idea of having an universal online currency and I wanted to know if I can use it in the 'surface web'.

user31421: Yes. You can use bitcoins in many places. There are Bitcoin exchanges where you may exchange your coins for USD or vice-versa. You can also use them on various websites like Newegg for example.

user5406: There are a number of applications. Bitcoin is e.g. used for

donations, e.g. Khan Academy
online-shops for digital goods, e.g. vpn, web hosting, mail servers, mp3s, computer games
mail-order companies, e.g. Overstock
booking flights and hotels, e.g. on Expedia
remittances
brick and mortar stores

You can find a more complete overview on the question Where can I find a list of merchants who accept bitcoins? 

31419: <p>I really like the idea of having an universal online currency and I wanted to know if I can use it in the 'surface web'.</p>
 31421: <p>Yes. You can use bitcoins in many places. There are Bitcoin exchanges where you may exchange your coins for USD or vice-versa. You can also use them on various websites like Newegg for example.</p>
 5406: <p>There are a number of applications. Bitcoin is e.g. used for</p>

<ul>
<li>donations, e.g. <a href="https://www.khanacademy.org/donate" rel="nofollow noreferrer">Khan Academy</a></li>
<li>online-shops for digital goods, e.g. vpn, web hosting, mail servers, <a href="https://libertymusicstore.net/" rel="nofollow noreferrer">mp3s</a>, <a href="http://www.greenmangaming.com/" rel="nofollow noreferrer">computer games</a></li>
<li>mail-order companies, e.g. <a href="http://overstock.com" rel="nofollow noreferrer">Overstock</a></li>
<li>booking flights and hotels, e.g. on Expedia</li>
<li>remittances</li>
<li><a href="https://coinmap.org/welcome/" rel="nofollow noreferrer">brick and mortar stores</a></li>
</ul>

<p>You can find a more complete overview on the question <a href="https://bitcoin.stackexchange.com/q/2089/5406">Where can I find a list of merchants who accept bitcoins?</a> </p>
