"That's bullsh!t!" you might say. No, it's BullZip! (Yes, I'm well aware of how cheesy a joke that was. You'll survive.) It uses GhostScript Lite, and it totally rocks. Plus it's donationware... so make sure you give them some love.
BTW, they also make a free MD5 Calculator that lets you right-click on any file and get it's hash... it even lets you paste in the hash from a website for a quick comparison. Good for making sure that SP1 download of questionable origin is legit...
Anyways, I just blasted my laptop and reinstalled Vista SP1 slipstreamed (not because of errors per-se, just time to clear out the software I don't need/use), and these were the first tools I installed. Forget Adobe... get BullZip PDF!