I have some computers and I need some ideas on what to do with them as a hobby?

I am currently in trade school for computers, and I really want to make it a hobby as well as a profession. I currently have about 4 old PCs (probably 4-5 years old), I have a Laptop, a tivo, a wireless network, and Im currently building a computer as well. What are some cool things I could rig up with everything I have (although not a ton) and not only have fun with it but possibly learn something from it too?

ANYTHING will help, I just want some ideas to apply the knowledge I'm gaining. (I have a lot of software too, so cross into that realm as well!)

I have some computers and I need some ideas on what to do with them as a hobby?spyware

Try inventing something new out of it. That's how Dell was created, created by Michael Dell while he was in University.

I have some computers and I need some ideas on what to do with them as a hobby?virus scan

1. you can make one a server

2. you can make one a dvr computer..but you have tivo so i guess no

3. you can heavily mod one and add a glass panel to the side and spray paint it

4. you can give it to me :D