http://www.pixelmator.com/ While Photoshop still can run circles around it on the feature level, the usability level and the fact that this is a fine example of OSX's Core technologies being utilized, its definately worth checking out. I wouldnt be surprised in a year's time that Adobe will start being forced to re-evaluate it's pricing monopoly. And im a Photoshop user of 13 years (thats a lotta $ in upgrades)
Ive noticed Photoshop elements doesnt quite do what 90% of users would like to do, and Photoshop has about 90% of features that people who have to buy it, don't use. Pixelmator seems to address this issue. And no, I don't represent or know anyone who develops there, im just enlightened at the moment
