hmmm since it is a laptop (i'm in the same boat) probably the only thing you can upgrade easily is the RAM. depending on how your memory sticks are set up I would put in another 512mb stick, just make sure it's the same kind you have in there now. if you're unsure, goto www.crucial.com.
once you find out there what kind of memory you need, goto www.newegg.com
that will probably be your best prices. you probably don't need 2 gigs of RAM, but I'll let someone else confirm that. unfortunately, graphics cannot be upgraded on laptops (except for a few exceptions). a RAM upgrade will make a difference in everything you do.