I highly recommend dropbox....it has never failed me and I use it a lot.
Dropbox encrypts your files....Downside is they have the key...The files are stored on Amazons servers I think.....
If you are paranoid about it you can use
TrueCrypt - Free Open-Source On-The-Fly Disk Encryption Software for Windows 7/Vista/XP, Mac OS X and Linux to encrypt your files within your Dropbox, That way you know your files are for your eyes only.
