Travis Swicegood:" Amazon's S3 service is experiencing it's second outage of the year. According to Amazon's status site, they're been down for roughly 6 hours right now. Sites like SmugMug are completely down as they rely 100% on S3 to serve photos from. Avatars on Twitter are broken because Twitter uses S3 to offload that content."

Arguably you could be surprised those services aren't using a caching proxy for hot files (typically they would be the recently added ones). But I suppose that would feel like running your own generator.

Or you could look at it this way - S3 is more like an offload of deep storage - instead of buying that honking great filer, you rent it. But a filer's not neccessarily the first port of call for serving files.

(10 minutes later) Oh, here's an update via Gigaom:

"Amazon S3 is used heavily by a number of services behind Amazon’s retail websites.  Those services were impacted, but the retail website did not show noticeable problems because it mostly uses cached data."