I only had one problem with it...
It was a good tutorial. Perspective is one of the trickier techniques to master (although it really is pretty simple once you get the hang of it), and I think you've done a great job with explaining it. The interface was pretty good, too.
My only problem with this tutorial is that, when you got to the photoshop bit, you took a short cut and just showed us the end result. I'm pretty sure a lot of people out there could use some some tutoring with coloring, shading, and manipulating images with photoshop, and I really wish you just explained everything, step by step.
But, as it is, it's a very good tutorial. One of the better ones here in NG.