A crash of Amazon.com's heavily used Amazon S3 storage service has caused problems for many Web 2.0 sites that rely on the service. You can find a status page for Amazon's service here.
Here are a few of the outages and problems.
Plurk, Twitter and Kwippy are having problems showing images loaded with Amazon A3. It sounds minor but it just isn't as much fun microblogging without the avatars.
Posterous.com reported problems posting different types of files.
Another site down is Smugmug.com - you can see their message here.
Slideshare.net reported problems related to the outage.
A video and photo sharing site called Phanfare also reported problems.
More discussion of the outages can be found here on Techmeme.
This is just a sample of the many sites affected by an Amazon Web Services problem. The cheap hosting service has become popular with Web 2.0 startups. There was a similar Amazon Web Services outage back in February, 2008 - see here.