I like the the low friction of mtgox but if libertyreserve.com is down, doesn't that mean that your dollars are stuck in a mtgox account?
I've seen a few sites that offer to convert small quantities (5 BTC) into online-only credit cards, but most of them have a lot of friction ($5 fee+%)
The bitcoin wiki lists quite a few exchanges, but many of them seem very very dodgy. Is there any reputational system that has emerged to know whether or not an exchange can be trusted?
This is easy. Use MtGox and set up a Dwolla account. Send an email to email@example.com
asking to withdraw to Dwolla.
It costs $0.25 per transaction, so you can get up to $1000 for that. Dwolla then can deposit into your checking account for you.
The disadvantage of this is speed of the process. You can only do $1000/day, and at times like this when everyone is trying to get money into or out of Mt Gox, there usually is a delay of a few days, as Magical Tux has to wait for previous transactions to clear before he has the capital in the right place to accommodate your request.