I haven't posted in here for a long time, but since I'm back I'll give my 2¢.

Many older Schwinns make excellent conversions, especially if you are looking to keep it cheap. I reccommend going with a Euro BB adapter and a cheap set of Bulletproof cranks with a sealed BB. For the cost of cranks, adapter, BB and a chainring and bolts you should be able to get all this for about $100, give or take. Which is roughly 1/3 the cost of a Mercier Kilo TT. Now if you want to go with a proper fixed hub laced to a 27" rim, these can be had for about $90 + shipping, so now you're 2/3 of the way to could-have-bought a Kilo TT...

See where I'm going with this?