Yes, increasing capacity of DVD's is a bliss in this matter, there is DVD-9 which has about 8GB of space to use

The new burners can write to it.
But giving my private stuff to a website (mozy.com, or any other) - I don't think so... I just don't trust them, never will. I'd need to encrypt the data with 256bit key just to consider leaving it there for a short while ;P