The SD790's retail price is $50 more than the 870's. The 790 has a better LCD screen, but the 870 starts out 7mm wider.
I'm looking at 2 Canons--the Powershot SD790IS AND the Powershot SD870IS. The 790 seems to have a little bit more than the 870 (like focal points). The prices are similar. Definitely want to go with 1 of these 2, just not sure which is better. Looking to buy this weekend. Appreciate the help--I've always gotten great advice on cnet forums!