If you look at my comparison chart of online backup services, you'll see a long list of several dozen different vendors that offer a dizzyingly array of packages and prices. Two companies stand out from this crowd mainly because of how they have combined the cloud-based services with a particular piece of hardware: 3X Systems and Global Data Vault.
Here is the idea: The hardest and lengthiest part of any online backup solutions such as Mozy and Carbonite is the intial "seeding" or copying of the files from your PC to the cloud-based storage repository. This can take days or weeks, depending on the amount of data and connection bandwidth involved. So what both of these vendors offer is to first put their box – which is just a PC with a big hard drive -- on your internal network, make the backup at LAN speeds and then you move their box to a secure offsite location after the initial backup has been completed. This way you get the benefits of online storage with offsite protection all in one package. You can also backup PCs that are located in various remote offices in one central place, too.
The box connects up with the PC via an agent that is installed and a locator service that marries the two no matter where they are across the Internet and how many firewalls and routers are in between them.
You can see how this works with a video screencast that I produced here(disclosure: this was sponsored by 3X). The two companies charge differently for their products, and depending on how much storage you need, you will prefer one over the other.