Originally Posted by squeakywheel
Lots of people have successfully made a fixed gear out of a vertical drop-out bike. You just have to use a "magic gear". You can find magic gears here:
http://eehouse.org/fixin/formfmu.php
You con't need to get that complicated any ratio will work. Put the chain on, add a half link if you need to, and then file the dropout just a touch if you need some adjustment. You need to keep on top of it a little when the chain stretches, but it's not too bad.
Done.