Buy one of those neat little back-lit LCD pixel displays and write a program to stream a News website (CNN or BBC maybe) RSS feed to it, then mount it on the wall behind your PC to impress your friends.

They usually have Serial cable interfaces so the coding is dead easy.
You can get the LCD hardware from www.Maplin.co.uk

There is a decent article about this on the MS website under "Coding4Fun" then follow the link to "some assembly required" (that doesn't mean assembly language by the way, its a bit misleading ).

I plan to do this if I ever get any spare cash.