Update Jul 02 2011: crossdomains.xml should be crossdomain.xml
Update Jun 29 2011: Updated S3 upload URL – no more security error
If you’ve ever wanted to allow people on your website to upload files to Amazon S3, you’ll know the only real way to do this is with flash – as it allows the client to upload directly instead of funneling all traffic through your server. You could write your own script for this, however there’s already a nifty little prebuilt tool I’m sure you’ve already heard of called Uploadify which can not only do the job for you, it can do so with great flexability.
For the lazy: Download the entire script here