Have you seen this site?

www.fixedgeargallery.com

Great collection of fixies, from all sorts of backgrounds. I can't start my day without looking at a few fixies from this site.

+1 to the flat pavement idea. +1 to the fact that I had a freewheel flip flop hub, and never used the freewheel side. A few people, instead of having a freewheel, put two different sized cogs on each side to help them get up hills, but since you'll be on flatter conditions...

Are you doing a build of your own? Or are you purchasing a track bike? Pictures, pictures!