Lpc2000

>> I've had a MAX202 working OK at 3.3V, so a MAX232 will probably be OK. The 
MAX3232 would be best, if you can get one, as it will be within its spec. <<

Also, the 3V parts aren't difficult to get hold of (at least not in the UK) 
and there are quite a few people making drop in equivalents. Intersil and ST 
do them to name two off the top of my head. Unless you have a big stash of 5V 
parts you need to use up, you really would be best off using the 3V part.