hey deuce,
i have two sony x-82b's (18.1", 1280x1024). each display has two video-in ports
1. a combined dvi/vga port
2. a pure vga port
so you can hook up two machines to each monitor and switch with a press of a button on the front bezel between the two.
i've had them for a little over a year now, and use them approx. 10-14hrs. every day - they still perform flawless.
hop on over to sony's site and take a peek - i would highly recommend them (there's a new model out now ... x-83 (?) i think). they also have a 23" widescreen model - in case you need to go "big"
also, if you have an ethernet setup between your pb and the dell, check out
km remote ($ 19.95), a utility that (perfectly) replaces the need for a pricey kvm switch ($120) - install on both, the pc and the mac and control both computers with one keyboard/mouse. i love the thing.
hth,
eff.