What to use my old, but decent, desktop for?

So my ~4-5 year old desktop:

Core 2 Duo @ 2Ghz
256MB 8600GT
4GB RAM
320GB 7200RPM drive

With a fresh install (literally 20 minutes ago!) of Windows 7 it still feels quick and wonderful to use! It is especially "fine" for simple web browsing, watching videos, etc.

No one has been using this computer, but I do not want it to go to waste - especially when it has a couple more quality years left! What can I use it for?


Thanks in advance
_
More info that could limit/help give ideas:

Sadly, I am going to college this year (I will be about 15 hour drive away) and am going to be buying a new (much more powerful and more gaming capable) laptop quite soon, and I will not be taking this desktop with me.
My family also has a "family laptop" that is a couple year old HP Pavillion dm3 with the Intel U4100 (dual core 1.3Ghz processor) which, other than for me, is pretty solid for simple web browsing and the other things my parents use it for (facebook, youtube, other basic streaming). So I want a solution that would let them use it (they are reasonably technologically educated, but it still needs simplicity) while I am gone.