Not Free... but very cheap
Take a look at Amazon's S3 Services
, while not free, it is dirt dirt cheap... rarely over a $1.50 a month for many many gigabytes a month. It uses Amazon's backbone, so you know its going to be around.
Be aware, this is online storage not a Flickr, Smugmug type site. You can backup anything, not just pictures.
I am using JungleDisk
which makes my Amazon S3 Drive look like a Network Drive on my iMac so I can drag and drop from Finder. I use JungelDisk's built-in backup client, however you can use any backup client that allows you to backup to a network drive. JungleDisk is available in Mac, Windows and Linux.
I use it and recommend it!
Here are the rates:
United States
Storage
$0.15 per GB-Month of storage used
Data Transfer
$0.10 per GB - all data transfer in
$0.18 per GB - first 10 TB / month data transfer out
$0.16 per GB - next 40 TB / month data transfer out
$0.13 per GB - data transfer out / month over 50 TB
Requests
$0.01 per 1,000 PUT or LIST requests
$0.01 per 10,000 GET and all other requests*
* No charge for delete requests
Europe
Storage
$0.18 per GB-Month of storage used
Data Transfer
$0.10 per GB - all data transfer in
$0.18 per GB - first 10 TB / month data transfer out
$0.16 per GB - next 40 TB / month data transfer out
$0.13 per GB - data transfer out / month over 50 TB
Requests
$0.012 per 1,000 PUT or LIST requests
$0.012 per 10,000 GET and all other requests*
* No charge for delete requests