I built this over the winter:

http://community.webshots.com/photo/...68014369ZmdEeX

It's the first ss I've built. The cog is a Surly and the ring is an old XT with no ramps or pins. I found the magic gear, so no chain tensioner. I can even use a qr rear hub because all it does is keep the wheel from falling out.

It's all I ride any more. My geared bikes are just gathering dust.