I'm all twitchy about backups. I want double and triple assurance that my stuff isn't all going to disappear. I used Mozy many moons ago when it was new, but backing up an iTunes library wasn't practical then. In the meantime I've used Dropbox and carried my iPod Classic with me (most of the time) and felt some assurance that should my apartment be torched I'd still be able to retrieve most of my stuff. Still, I'm always a little nervous that if a power surge, fire, flood, or other incident that wiped out my office occurred, so would all of my backups be wiped out.
MacWorld reports trotted out Dolly Drive, so I started re-exploring the idea of cloud backups. I found out that these services now will send you a DVD of your data in the event of a crash, so that makes them useful to me. (Downloading an iTunes library is not very useful; it takes about a week to back up a normal-sized hard drive to an off-site storage area.) So I checked out Dolly Drive, revisited Mozy, and checked out Backblaze and Carbonite (the latter mainly because as a member of the TWiT army I hear ads for it constantly).
I have had mixed experiences with Time Machine, but I tried Dolly Drive anyway because it looked like a good idea and has a cute sheep icon. Signup was riddled with annoyances, which I'm willing to overlook because it's probably overloaded as a result of the MacWorld hype. It created an online backup drive easily enough, and I left my Air on for 72 hours while I worked and slept. It uploaded about 12 GB of my data, and then the app crashed. I restarted it, and the damn thing started from ground zero. That right there makes it not reliable enough for backup, so I deleted the app and canceled the service. Still...cute icon, though.
Mozy is cheap and has worked well for me in the past, but as far as I can tell it doesn't allow backup FROM an external drive. Which I need because I keep my iTunes media on one. They're also reputed to be putting data caps on their backups, and that may or may not an issue depending on the pricing and caps. I'm not really a power user with thousands of movies, and their prices are low to begin with. But really the no-external-drives thing is the deal breaker, as it is with Carbonite. I understand why they have that rule, but for those of us with tiny Air hard drives, being able to back up only the internal drive isn't terribly useful.
That leaves us with Backblaze, which seems according to its information to do everything that I want and which some of my most respected bloggers use. It also has a free trial. In theory, it'll back up my Air drive and my external iTunes drive, do silent incremental backups, and send me a DVD if a power surge knocks out everything on my desk. It has a useful control panel that excludes obvious things automatically but lets you add stuff yourself (I don't need my Dropbox folder backed up yet again, for example). So far it's been backing up for 24 hours. I think it'll take about a week to get a full backup into the cloud; it lets you set a slider to give greater or less priority to the bandwith used for the backup, but since I'm snowed in and streaming a crapton of "Bones" from Netflix I haven't cranked it up. We shall see.