WebDesignerWall.com has put together and posted a list of 30 undocumented “secret” keyboard shortcuts in Adobe Photoshop. The list is very detailed and documented with image screen shots as well. You might already be familiar to some of them, but I’m sure you’ll see some new ones that will speed up your productivity, specially if you work a lot with Photoshop.
PS. WebDesignerWall also has a lot of great Photoshop tutorials.