Many offices used this sort of thing, we've had "dongles" for as long as I've been here. They're much more useful than physical keys, and allows restricted access to servers (which can be a good thing). Still it hasn't totally stopped people stealing stuff, so the expensive bits are also behind physical locks during the night.
Our Singapore offices have biometrics - a fingerprint scanner for door entry. That's so nifty, evil, but nifty evil.