The trouble with lanyards is they get caught, especially annoying if you're crawling under desks. Plus once you start adding the paraphernalia of all but the most state-of-the-art centrally controlled door locking systems you end up with a wide variety of swipe cards and keys which mean it's equivalent to carting a good pocket full of crud around your neck. I don't want to walk around with my ID badge, two USB sticks, a SecurID fob, two RFID fobs and twelve keys bouncing off my chest.
How about the tried and tested solution - name badges. Your name on one line, "IT Services" on the second line, and the corporate logo on the left hand side. Make them the fancy magnetic clip type so they don't ruin clothes and can be pulled off if they snag. Simples.