I've spent quite a bit of time banging my head on the wall trying to figure a way how to do that in older versions SQL Server. I believe you can build user defined aggregate functions in 2005, which should be able to solve that problem.

Amusingly, MySQL has a built in function, group_concat, that does exactly that. It's terribly nonstandard, but probably very handy for exactly this sort of situation. I'm guessing it is an example of itch scratching on somebodies part.

Jay