Spideroak.com works too. It automatically backups your data to the cloud (securely encrypted!). It synchronizes your data across multiple machines (and multiple

Spideroak.com works too. It automatically backups your data to the cloud (securely encrypted!). It synchronizes your data across multiple machines (and multiple OS) and you can access all past versions of your files. It's free if you don't need more than one or two GB. It's the ideal backup tool for researchers that don't generate tons of data and want a simple backup solution.