> Don't bother with a shim. Just get it replaced.
I meant while I was trying to find a replacement.
> Non drive side crank arms are cheap! I bet your LBS has one laying around you could use.
Actually, no - I went to most of the shops in London and nobody had a matching crank that would fit my bottom bracket. I was trying to find a match to avoid having to shell out £100 for a new crankset. Hence the need for the shim in the meantime.
Just in case any of you are curious - beer can shim worked a treat for my 10 mile commute for the three or four days until I caved and shelled out the £100. On the plus side, the new cranks are much better.