Dell hasn't certified any USB 2.0 cards for this (or any I think) server.

This doesn't mean it won't work, but if you buy one from Dell's "software and peripherals" division, it is a guarantee that it will work in a Poweredge.

Search these boards for the term USB and you may find some people posting experiences with different model cards, maybe some even in the PE2600.

yep indeed unsupported but doesn`t mean it won`t work. Just means it wasn`t verrified.

PERC/CERC CARDS tend to interfere with expansion cards. Result is that card is NOT SEEN until PERC and or DRAC card are removed.