Vandelay Design brings us a nice compendium of Photoshop techniques. Some are really nice, and some are not what you may want to do... but there is a lot of variety and everyone should be impressed by a few.
30 Photo Manipulation Tutorials for Photoshop | Vandelay Design Blog:
With Photoshop, amazing results are possible for photo manipulations. In this post we’ll feature 30 tutorials for creating your own photo manipulation. The tutorials shown here will teach a wide variety of techniques and will work towards end results of all kinds."