thanks for the replies
Interesting thought prathmann. Am I right in thinking you mean removing the (destroyed) rear derailleur completely, shortening the chain so it's the right length on one cog and getting the tension right by moving the wheel horizontally?
sorry I've never delved into the single speed thang :/
Yes, that's the idea. As long as you have a chain tool along you could at least cobble it together well enough to ride to the nearest town that has a bike shop where you could replace the derailleur. Horizontal dropouts work fine with QR as long as you have a decent skewer - standard Shimano and Campy work well, but lots of the weight-weenie ones don't hold firmly enough.