Yes I'm also looking at a refi -- my second in 2 years, but could lower my rate by more than 1 pt., saving me about $400/mo.
While Tantal wants to pay off the mortgage as quickly as possible and thus prefers the 15 year, I am more interested in a lower monthly payment, so the 30 year is fine for me (could get even lower with a teaser rate on an ARM, but with the uncertain economic climate today, prefer the security of a fixed rate).