Depends on what you have already... and assuming you're talking newer campy stuff...

I needed a campy cassette lockring tool... oh, and an actual lockring (I must have missed the memo saying that campy cassettes don't come with lockrings - note there are 2 different rings - one for 12-13T, and one for 11T)
http://parktool.com/products/detail....t=4&item=BBT-5
http://www.excelsports.com/new.asp?p...jor=1&minor=10

I had this wrench for the BB already which works on shimano & campy outboard bearing BB's:
http://parktool.com/products/detail....5&item=BBT%2D9

I also needed an extension for my wrench to reach inside to tighten the crankset bolt.

... and if you've been reading the F campy thread, uh, don't forget a torx wrench for the brakes