The A330 is the best plane in US's fleet in terms of entertainment!!
-5 or more movies to choose from
-sitcoms & TV shows
-CDs which are programmed so you can choose what track to listen to, instead of in order, as on any other plane
-nice-sized screen for a PTV!
I really liked flying the A330 last year! It's a comfortable plane, and they're all new, which is a plus. I would love to go on it again, and highly recommend it for Trans-Atlantic flights and PHL-SJU, where it is also used.
As for PHL-SFO, there are three flights listed on usairways.com:
US 63- A320 departs PHL @ 8:20am
US 65- A319 departs PHL @ 2:15pm
US 197-A321 departs PHL @ 5:55pm (this is probably your flight)
A310/319/320/321/333, ARJ, BN2, B722/73S/733/734/735/73G/738/739/744/757/753/767/763/764/777, CR1/2/7/9, DH6, 328, EM2/ERJ/E70/E75/E90, F28/100, J31, L10/12/15, DC9/D93/D94/D95/M80/M88/M90/D10, SF3, SST