Tried Carbonite, way too slow! Any suggestions?

Hello,

I am trying to figure out a good system for on-line back-up of my wife's new MacBook Pro. She has Carbonite for her PC and has been very happy with it, so we ordered it for her MacBook, but after 8 days, it had only backed up 7 GB of data and still showed that it had over 112 GB to scan! We cancelled the Carbonite service, but now I am trying to figure out what to do for her?

I have an External HD attached to my iMac that is dedicated for the Time Machine. I can see that the MacBook Pro has the Time Machine on it, but she doesn't connect to an External HD, and it would be fairly inconvenient to do so with a laptop.

What are the rest of you doing? Is there a good alternative to carbonite that works better with Macs? I have done some research, but I still don't know... Has anyone heard of, or tried "ChronoSync"? What about the iCloud? Does it work like carbonite?

I just really don't know what to do, but I know that we need to do SOMETHING!

Any help would be appreciated!

Lincoln