As an alternative to Dropbox, you should check out https://www.sugarsync.com/referral?rf=tetx5o7bz6i2.

Full disclosure, yes that is my referral link.  However, by signing up using my link, you and I both will get an extra 500 mb of free storage, on top of the free 5 GB.  Or, you can just go directly to their sign up page here https://www.sugarsync.com/free/.

While it's best to still use a tool like Truecrypt in conjunction with SugarSync, they do encrypt your data automatically upon upload.  That, combined with the 5 GB of free storage is hard to beat.