Hate to be a pedant, but...
Airbags are actually a dangerous idea without seatbelts. In a frontal collision, you're already moving before the airbag fires and, given that it fires at head/shoulder level, guess what gets snapped backwards when it does fire as the rest of you is still trying to travel at the same rate as the car was a moment before? The whole point of an airbag is to stop your head moving too far forward and then whipping back into the headrest. The seatbelt's job is to immobilise the rest of you, which is why cars with airbags (SRS or *supplementary* restraint system) also usually have seatbelt pretensioners.
If you really must drive around without a seatbelt on, you're better off disabling the airbags. Car manufacturers have known this for a long time, which is why you can disable the passenger airbag (Toyota owners, open the passenger door and check the end of the crash padding, you'll find a keyhole for just this purpose. This is not for use in pre-divorce situations, though) for those who, for medical reasons, cannot wear a seatbelt. Without a seatbelt, you're slightly more likely to survive if the airbag stays the hell out of it, assuming you don't go through the windscreen instead. Another little tip: Always make sure the whining git who can't wear a seatbelt is in the FRONT passenger seat where their flying corpse isn't going to decapitate any other poor sod.
Off topic? Yep, surely, but tapes are still the ultimate in backup reliability  so I didn't really bother with yet-another-mechanical-hard-drive-point-of-failure false sense of security product. Just like airbags, really. The best way to stay alive is practice defensive driving, assume every Volvo is on auto-pilot with a very primitive AI, let every BMW pass safely and stay the hell away from the noobs and flat-cap-and-glasses mob. The best way to back up your data is still "do not trust hard drives or optical disks that have a shelf-life of a cheap loaf." Those of you using the DVD backup and archive method, use Taiyo Yuden based disks, preferably DVD+R, and nothing else. Trust me on this one.
 A bulk eraser has yet to be made that can erase a DDS tape successfully. http://www.cs.auckland.ac.nz/~pgut001/pubs/secure_del.html