Thanks Mikal. I am visiting family at the moment, with no Arduinos handy to test, but when I get back to work, I'll add this to the String lib.
FWIW, though, this library is not part of the core distribution, to my knowledge. It isn't in the svn, and isn't in the distribution, though that'd be nice. There are also some optimizations I'd like to get to as well, but the day job keeps getting in the way 