For everyone above and anyone else who reads this thread... these are all solutions to the problem. I've had experience with all of them. From what I've learned, from a scale from hardest (i.e. I hate cars and never want to work on them again... until next weekend) to easiest (this is sweet why don't I quit my job and do this all the time?):
1. C-clamp (bad... VAG says rotate, so rotate. One of these days I'll dissect a rear caliper and take pictures to show everyone why)
2. Socket adapter thing. (After 2 hours per side of grunting, pressing, and twisting, I got those suckers back in)
3. generic piston tool from ECS or Autozone (it's great, until it breaks -- again, I got 4 uses out of it. Once on my stock brakes for my VR6, another time after I took those off and sold the calipers, but compressed them for the buyer so he wouldn't have to mess with it, then again on my friend's B4 Audi A4, and now on my Dad's b4 Passat, which was the killer).
And eventually I'll add the number 4 on that list, which is either the real VAG tool from Zelenda or the German Auto Parts tool. Both look better than the generic kit but I haven't tried them yet.
The generic tool is fine, but when you invest in a tool you usually expect it to last a long time, which is why you bought it, because you thought "I might as well get that, because I bet I'll use it a lot". It will be fine as long as your calipers aren't super stubborn, but if you find yourself searching for a wrench to put on the end of it... stop. It won't take too much to break it.
So, I spent about $45 on that generic tool, which means each time I used it I got about $11.25 out of it. I would have paid someone at least $15 to do it for me, so I suppose it was worth it in the end... but man, I'm gettin' the beefier tool now.
Consider this a product review.