cPanel backups of each site daily and I download a copy of those once a week. My host also have R1Soft backup system. My sites aren't busy enough to warrant daily downloads. Then about once a month I write all the backups to dvd and store.
I have a cron job that runs once a day backing up the database. My host also does daily backups of everything.
twice weekly for ZenOK online backup. I really love how I can just plug the external HD and it does it all on its own. Would love to give ZenOK a try for backing up via wifi!
Dedicated server - image to second disk nightly. Laptop - weekly image to 3 x different 2.5" ext. USB drives.
I know - I started a thread in GeeksChat about going *nix but there are a couple of things I need Windows for and I don't quite have the room in the house for separate machines (and the wife definitely wouldn't understand! ).
What do you need Windows for? Seriously? The ONLY time I boot into Windows is to do security updates or play World of Warcraft (my poor ol' notebook is too old to effectively run WoW via Wine). Everything else is done via Linux. Everything. Here's what I do. I have an external drive that is dedicated strictly to Linux. I've set up the boot parameters via the BIOS to look for the external drive first. So if the drive is plugged in, the notebook boots to Linux. If it's unplugged, it defaults to the internal drive and boots to Winderz. I'd install another hard drive in the notebook, but trying to find a drive caddy for the damned thing is virtually impossible at this point.
TBH time is the only real limiting factor; I don't have enough of it to properly migrate over at the moment. When I eventually get to go full-time self employed I'll have the time (and inclination) to do it (don't get much cheaper to run than open source!), and - like you - will probably go down the dual-boot route (or maybe use WINE for what few Win-apps I might need). SAGE is the main one that won't move over and my next most-used app is Photoshop (GIMP will probably do for what I need). There are plenty of email clients and Open Office for the rest of the day-to-day office tasks and we're there. One of these days ...
http://www.techrepublic.com/blog/10things/top-10-linux-financial-tools/372 GIMP is good, and go with Libre Office rather than Open Office. The Apache Foundation now holds the GNU license to Open Office, but they're not really doing much with the software. Libre Office is the fork of Open Office and is being kept current. Anything else? (There really is no reason other than laziness to not make the switch.)
Daily backup of database, monthly backup of whole site. Also backup taken immediately before any software changes or updates.
Beauty of my backups are they're cron driven and then sent to a remote FTP server. Hence, I do full backups every night.