Nice Warborg!
Any chance you can provide us with a detailed list of parts? It'd be nice to put one of those together, but a lot of us have never stepped foot in a skate shop, and wouldn't know where to begin.
Well, all I asked for was an inline skate wheel, including the bearings and the axle bushing/plastic spacer that fits through the middle of the bearings. They charged me $2 for an old used wheel and some bearings from a repair kit.
Aside from that, I used:
1/4" threaded shaft from AutoZone
Small encoder wheel from OscarControls
Metal caster wheel from OSH
Nail Plate from OSH
Volume Knob from Radio Shack
Predrilled PCB from Radio Shack
Kiningston USB mouse that I had laying around.
Various nuts/bolts/inside tooth lockwashers
I think that's about it... Pretty much a bolt-together design, aside from remote-mounting the optics from the mouse to the PCB from Radio Shack.