I currently backup to a removable USB hard drive. Hence, I only have two copies, one on my internal hard drive and one on the external, and both are located in the same physical place. Certainly not a wise backup solution. I have recently added a second USB hard-drive, but I have not set it up yet with my backup software (SyncBack Freeware http://www.2brightsparks.com/syncback/index.html). I will have that working in the next few days. However, I am still missing a key piece in the best of Disaster Recovery Plans (DRP) solutions; remote, internet based, backup.
There are numerous services to choose from, but to make the selection process a little easier I found the following review of 27 online backup services on About.com. Hope you find it helpful. I have yet to select a service, but once I do, I will certainly share.