They say backing up is hard to do, but it definitely gets easier every day. It’s especially important to get your data off site so that if your main operational facility is burglarized or otherwise damaged, the resulting data loss doesn’t put you out of business.
Internet-based backup service mozy just released a (beta) Mac-based client that makes backing up data to an off-site location dirt-cheap and dead-easy. It’s also the only cross-platform service that I’m aware of. Check ’em out and make sure your data’s getting off site.