Backupify for a while now to backup my GMail, Google Contacts, Flickr photos and more. I have a post from January explaining the free service.
They have now enticed me with an opportunity for a free Premium account for five friends. If five people I invite through their site all sign up for the free account, each of the five, get a free subscription to their Premium Service.
So if that sounds good to you, e-mail me at MarkStout at Gmail (replace the at with an @ of course) and I'll submit you. Then when you get the invite be sure to follow-up and sign up. If all five do, then then each gets a Premium account.
In the interest of full disclosure, there is something in it for me. I'd get a Business account for free, and also entered to win an iPad. The sharing of one in the family is somewhat problematic, so that would be useful.