Where did you get the disc pattern?
After many searches I found one I like but the resolution was poor so I used Inkscape to turn it into a vector. Free, easy to do an very effective. I’ll upload it later.

Did you make your own h-bridge?
I was lazy, used an L293D motor controller IC. It’s a little bit overkill since it’s designed for two motors but I have plenty of them lying around. I’ve yet to make my own h-bridge, in hindsight this would have been a good project to do it on since the motor has little resistance (can’t stall like in a robot application). The transistors were for my range finding, I’ll mention that shortly.

I’m curious about your distance code too
It’s non existant! The range of the method was just not enough 30cm, tops. I should have realised that since I’ve used this style of range sensing in the past.
http://letsmakerobots.com/node/2907
That’s what I was using. I will eventually buy the same IR sensor you were using. Probably in bulk because my robots need to see too! It’s frustrating to have buy them because until now my parts were easily less that £5 but I really want the range sensing speed change as that’s the bit that caught my attention in the first place.