Anyone ever thought of using a fixed trials hub, a singlespeed cog, and cassette spacers for a fixie? Chainline adjustability would be a cinch and changing cogs would be a cakewalk. Since the cassette pattern is standard, cog availability wouldn't be a large issue.

http://webcyclery.com/home.php?cat=419

What would the negatives be? The wheel would now have dish, but I'm not a big believer that makes a difference for someone like me...

(I posted this deep within another thread, but want to start a new thread for visibility)

baker