There;s several apps for the mac that do the trick - just do a search on download.com. I'm using one called photopage (
http://download.cnet.com/downloads/0...st-7-2.5962714) which works fine, and also creates gallerys, and it's free. Muchothumbs looks pretty good too but you have to register it for $30.00. Both of these have both OS X native, and classic versions, and there are others available as well. And of course photoshop rules.
Whatever you do, don't go over to the dark side - Macs Rule! If you need to run some PC apps, use Virtual PC.