Pour ma part je sauvegarde (en plus des DVD-R et disque externe) sur Amazon S3 :

Storage
$0.18 per GB-Month of storage used

Data Transfer
$0.100 per GB - all data transfer in

$0.170 per GB - first 10 TB / month data transfer out
$0.130 per GB - next 40 TB / month data transfer out
$0.110 per GB - next 100 TB / month data transfer out
$0.100 per GB - data transfer out / month over 150 TB

Requests
$0.012 per 1,000 PUT, POST, or LIST requests
$0.012 per 10,000 GET and all other requests*
* No charge for delete requests