The
Acronis TrueImage thread has a sort of discussion on could services. At the moment there are a fair few options out there.
Bitcasa - It's currently free while in Beta, I've not used it for a while as it was very buggy but it could have shaped up nicely now, the gist of it is you drop everything you want clouded into specific folder(s) flagged in Bitcasa, then these folders are automatically synced with the Bitcasa cloud. If it's cheap when it goes final and they sort the software out it will be a good solution I think.
Google Cloud - I tried it for work, don't really like it at all, I don't think its particularly user friendly or convenient. Pricing is on the link, first 5GB is free, with data rates for beyond that on top.
Dropbox - Which I'm sure everyone has heard of and probably played with, I don't really care for it that much and stopped using it, it's more for people that need to access their files remotely or share them a lot, which I don't. Their free package is 2GB minimum and up to 18GB (500MB per referral).
Others that have been mentioned before are Carbonite and Mozy, I've no experience of them though. There's a website ranking them here that might be useful for a quick scan through to get an idea
http://www.cloudstorage.org.uk/lol
this thread brings the whole discussion full circle