Ok, that title sounds like a spam, but I am using this service, I dunno, for like a year or more. It's great for wordpress backups, probably tons of different kinds of sites. Be aware free version have 2G storage limitation 5 websites and 5 databases. Here's tutorial on how to use it on a shared hosting (and any other for that matter) .
[video=youtube;uGR-i3W6xq4]http://www.youtube.com/watch?v=uGR-i3W6xq4[/video]
[video=youtube;uGR-i3W6xq4]http://www.youtube.com/watch?v=uGR-i3W6xq4[/video]