The Photoshop basics get me around for casual UI mocking -- layers, blending options, gradients, free transforms -- but I haven't mastered the shapes or pen too

The Photoshop basics get me around for casual UI mocking -- layers, blending options, gradients, free transforms -- but I haven't mastered the shapes or pen tool in PS. Illustrator is where I head for scalable vector stuff (duh). Despite having seen some crazy, crazy awesome wizardry with the Photoshop pen tool, in AI the pen tool is much more manageable and powerful IMHO, especially in conjunction with the all-powerful Pathfinder.