Used oner of those for years to logon to our mainframe from my PC at home. They work great, but need renewed periodically as the battery runs down. Each year I turned in the old one for a new one as that seemed to be about the battery-life of the thing. Mine looked like an overly thick credit card.
Ron, I have been issued, and have used, the RSA SecurID in both the keyfob and card for corporate intranet access since 2000. Battery life is 3 to 4 years, based on my experience, as the SecurID Fob issued to me in early 2002 lasted until mid 2006. My current employer has a standard 3 year replacement procedure that I just went through.