I'm selling my old race bike (since I have a carbon fibre one now): it's a 54cm Genesis Flyer, a fixed-wheel/singlespeed road bike. These cost £649.99 new. I'm selling mine for £200 ono. It would suit someone around 5'7″-5'11″, depending on torso length and preferred reach. Google 'Genesis Flyer review' to see how good it is. 

And bear in mind that this one is better than the new ones. It has a carbon fibre fork instead of steel; a carbon seatpost instead of aluminium; the rear wheel is better, as it's (re)built around a Miche track hub instead of the Formula one it came with; and it has an upgraded 165mm Sugino RD2 track chainset. It also has better 'chain tug' screws and brand new Specialized Roubaix Armadillo Elite tyres. Frame is Reynolds 520 steel, pedals are flat/clipless double sided ones (Wellgo, I think), brakes are Sora. 

It's set up now with a 48×18T singlespeed freewheel (72in gear) and normal drop bars. However, I'll throw in 14 and 16T fixed sprockets, a lockring, and a spacer washer for the rear hub (this goes behind the fixed sprocket when it screws on, to fine tune the chainline). It doesn't have mudguards, but Crud Roadracer guards will fit fine and you could fit conventional full-length mudguards with some bodging.

It would be a good bike for training/commuting in winter, as there's nothing to go wrong with it. Or you could race time trials on it, which is what I did. (Best 10-mile time on this bike, 23:10.) 

I'll stick a picture of the bike on here shortly. Let me know if you're interested. Otherwise it'll go on eBay.

cheers