I don't know if your organization has issues with volunteers, "lost" or M.I.A. keys, or just not knowing who left the shop a mess after hours. We did, but after looking into all the options ( http://www.bikecollectives.org/wiki/index.php?title=Keyless_Entry) we were able to get a smart card (RFID) reader donated for our shop door. This has worked out really well so far.
A log is kept of who uses the shop and when for accountabilities sake.
Smart cards (http://www.hidcorp.com/technology.php?tech_cat=1&subcat_id=9)
can be purchased at any locksmith for the same cost of getting a traditional key cut, but they don't work until they are "registered" with software that controls the door.
Smart cards cannot be copied.
If a card is lost or there is a problem with a volunteer that can't be
resolved in a civil manner -- the card can be denied future access. Luckily we haven't had that anything besides "lost" keys.
- Access to the shop can be limited to the hour, so if we wanted to we could
incubate a volunteer by only giving them access to the shop at certain times.
- A magnetic contact on the door gives us a count of roughly how many people
use our shop. We realize that some people hold the door for others and some go in and out more than once -- while those might cancel each other out, it is a rough estimate.
- We installed the smart card reader at "butt" level. So if it is in your
wallet you can open the door without taking your hands off a bike with the "butt swipe."
- No personal information is stored on the smart (RFID) card, there is just
a pre-programmed number that has to be an inch away for a card reader to detect.