What Can I Do With...

Okay, so I have a few computers & laptops... what should I do with them?  - I have a lot of spare time on my hands at the moment...

Laptop:
1 - My current laptop, running Ubuntu & XP (Dual Boot)
2 - Spare laptop - also running Ubuntu. Has XP, Win7 & Solaris in VMWare

PC's:
1 - Running Windows XP
2 - Ubuntu server

Can anyone think of anything interesting I can do with them?

is boinc like donating your pc processor to another pc?