I'm actually in the middle of expanding/renovating my Star Wars room. I'm actually going to have 2 small rooms, side by side, so I'm very curious and thankful for everything said in this thread.
My carded figures are currently on pegboard with 6 inch long hooks, which allows me to put them all on the wall, even though you can't see the fronts of all of them. I find it works really well, and if I like, I can rotate which figures are actually being displayed.
On one of those "Expand-A-Shelf" deals, though, I did drill holes for Ultarama pegs. It's not working out too well, though...
The majority of my collection contains carded figures, so with my expansion, I'm buying 2 of all of the ROTS figures so that I can display them both carded and loose. However, I've been really torn as to the best way to display the loose ones. So far I've just got a few on a couple of bookshelves on REAL Stands, which are very effective at keeping them standing (to avoid the dastarly domino effect).
I must say, Derek, those stepped shelves are incredible. Those are exactly what I'd like! Are those the Expand-A-Shelves you are referring to? I'm not familiar with them. Please, tell me more!