I used to use S3 to backup data on my mac mini via JungleDisk. I was paying somewhere around $10-15/mo in storage costs after the initial fee of uploading the bulk of the data. Unfortunately after a system upgrade (not sure when or what specifically), the automatic sync w/ JungleDisk just stopped working. For several months none of my data was being copied back to S3.

What I really need is simplicity that _just works_. I found that in Dropbox and haven't gone back since. I use it to back up ~100Gb of data. On my other machines I just choose not to sync the larger directories and everything works perfectly.