RROD & Backing up game saves?

My Xbox 360 got the dreaded Red Ring of Death over the weekend. I've only had it 14 months, so it's well within warranty. I also purchased the BestBuy 2 year plan when I bought it, since I didn't know MS would increase the warranty.

My first question is: Is there any advantage going through BestBuy as opposed to Microsoft directly?

Secondly: Is there any way I can backup my saved games before I get it fixed? I suppose I could take the harddrive to a friend's house to use on his 360, but can you backup saved games to a flash drive or USB hard drive? I don't want to have to go buy multiple 360 memory cards.

Thanks,