I use s3

I use Amazon s3 for my backup. It is pretty nice, cheap, but not all that easy when compared to what is out for windows. As a mac user, I am more limited on what I can use for backup. Mozy and carbonite do not yet have mac versions. Because of the nature of s3, no product built on it can do rotating backups (where you have a backup of every file for the past n days). However, for people looking to store 30GB or less, amazon is probably cheaper. If you need more than that, mozy and carbonite offer unlimited storage for less than $5 a month! (so long as all drives are directly attached to the computer)

What S3-aware software I do use is jets3t and jungle disk. These two programs cover about any possible need I would have for there services.

• files to send to the general public
• self-expiring url's when you don't want to leave something publicly avabial
  
• share files with other s3 users only (by there email address)
• encrypting/compressing files for upload

There are plenty of programs that use s3 these days, but those two are the only ones I use.

There are drawbacks to s3 over other online backup programs. One is s3 has no native directory structure. The other is s3 has no means to rename or copy data. Even meta data on any given key (see wiki page for definition of terms) can not be changed. Lastly, there is a bug with files larger than 2GB. This is a high priority for them, but for me, it is not that important.