Now there's a dumb name for what is now a pretty powerful application! Back when OS X came out, and even as recently as Panther (10.3), Preview was pretty much as it sounds, an application for looking at images and pdfs. As of 10.4 (Tiger), the name really no longer fits…

For example, you can now resize, crop and color correct images (and save them out any number of different formats). You can annotate pdf documents and fill in pdf forms.

Check it out. It might just do what you need! If there were one thing Apple could do to make it invaluable it'd be to add the ability to edit pdfs, including add / delete pages (yes, I know the latter can be done in other apps); maybe under Leopard?