I use crashplan and it took a long time for the initial backup. What I did when I first set up crashplan was do a local backup, then have crashplan just back up the newer stuff online. I slowly added folders to my online backup until everything was backed up. That was I was sure the newer stuff was always being backed up.
Rebecca, I don't think it should take as long to back up after a crash. It'll say that it will take that long, but it shouldn't back up the same files again - unless there's some setting that's making it do that.
Alina, What's nice about crashplan is that you can have it back up to an EHD and it will keep track of what's on the drive, so you can always plug that drive back in and it will update the more recent files onto it. Having an EHD backup is a good idea, anyway, even with an online backup, because of the time it would take to recover all the files from an online backup.