There are good instructions here about getting going with S3 on EC2.  I just wanted to let people know that I found s3fs already installed on my Wowza EC2 instance, and in a different location than in that forum thread.

After creating the /etc/passwd-s3fs file, I mounted the bucket with the commands:

• sudo mkdir /mnt/bucket
• sudo /usr/local/bin/s3fs bucket-name /mnt/bucket