If you haven't heard about it, Amazon had an outtage the other day with some of it's shared services. Here's a great article explaining "what up with that"
http://www.roughtype.com/archives/2008/02/why_s3_failed.php
Here's a quote from Amazon about what happened:
Early this morning, at 3:30am PST, we started seeing elevated levels of authenticated requests from multiple users in one of our locations. While we carefully monitor our overall request volumes and these remained within normal ranges, we had not been monitoring the proportion of authenticated requests. Importantly, these cryptographic requests consume more resources per call than other request types.
Shortly before 4:00am PST, we began to...