PostPoints tip: My usual nag--backup your data

This week began with news breaking of how Microsoft lost the saved data--contacts, calendar, to-do lists, photos, notes and more--of up to a million users of T-Mobile's Sidekick smartphones. That makes it a better time than usual to renew a reminder that should be familiar by now: Back up your data. Now, not, later. If you run either of Apple's last two versions of Mac OS X, you already have an excellent backup application in the form of Apple's Time Machine and only require an external hard drive to get going. Microsoft's upcoming Windows 7 will include a capable backup tool too. Everybody else, consider the cheap backup options I reviewed in my column and on my blog last year. Which one you use isn't as important as your picking some kind of backup application and making it part of your computing routine.