That bot and many other goodies I run on my home-server.
Need of it was emerged when more than one computer was appeared at my home.
At first I bought wireless router (D-Link DI-624). Unfortunately, as it turned out later, I can't fully use my home network (Corbina-Yaroslavl): it is impossible to remain both in LAN and on the Internet at the same time (Internet is accessed via VPN, router doesn't support static routes :(, and I can't connect to VPN from more than one computer - it's limit of the provider).
Therefore I decided to buy old computer. I installed Linux on it, supplied it with 3 network cards and made it a router.
Initially I bought Pentium II, 400 MHz, 80 Gb, 128 Mb. Later I changed it to P4-2000, 512 Mb (I carried Linux with hard-disk to new computer without any problems - that's good :) ).
And now it's good that router was so weak - with normal home server I can do many interesting things :)
These thing are installed on it at this time:
Router - iptables, NAT
mail-server (at this time it doesn't work, I don't need it actually, but I want to bring it to normal state)
IRC-bot (I had to turn it off, because inter-LAN IRC-server doesn't allow to enter more than 1 or 2 clients from one IP)
World of Warcraft-server (it was on P2 already, it eats about 400 megabytes of memory easily :) )
If I remember, I will add more here...
Also I plan to make:
Video-broadcasting (TV-tuner is installed on the server), using VLC, or something like it
Something about VoIP (I don't have any definite ideas)
I plan to move to unlimited plan, and setup web-interface for downloader (mldonkey)