Cost of servers & bandwidth 
scumola: I go through http://serverpronto.com for my hosted machine.  It's a real machine (not virtual or shared) and I've got real root access to it.  It comes with Fedora 3 or 4 and I upgraded it to Fedora 6 remotely, but I'm a little intimidated to upgrade beyond that without having physical access to the machine.  $30/mo, 200GB bandwidth @ 100Mbit, 30GB HD, 256M ram for starters.  There are other options.  I use S3 for storage of large data items.  All-in-all not too bad for a good hosting setup.  I host about 10 semi-active sites on that one machine.  My S3 monthly charges are $1 for my personal backups of important data and $30 for website data.I know that there are plans out there for unmetered monthly data that's capped at a certain speed for a fixed low $$/mo (30-ish), but they tend to be virtual hosts.  You could get a real host (for the site and good performance) with capped bandwidth and a second host with unmetered bandwidth for the storage and delivery of your streaming media.  Best of both worlds kinda, but again S3 charges so little, that it may be better to just go through Amazon for the media.