http://support.microsoft.com/default.aspx?scid=kb;en-us;818368 for vs.net, and

http://support.microsoft.com/default.aspx?scid=kb;en-us;201240 for vs6 (looks like it's best to use interdev)

I tried and used this for a while, and it does work.  The only downside I would say is that you don't version table designs etc, but they can be backed up.  Remember if you use UDF's a lot, these don't seem to integrate well with vs6 (as they came along after vs6).  In all honesty, I haven't tried UDF inetgration in vs.net (any version).

If you're interested in VSS, there is a book http://www.hentzenwerke.com/catalog/essvss.htm I would reccommend - it is all the *other* stuff about VSS, the stuff you don't read every day on msdn

hth