I'm always interested in seeing new open source password management solutions. Unfortunately being limited to user/pass/location is a deal-breaker for me. The only decent tool I've found that provides additional fields is KeePassX.
There is one web app that has this potential, Siptrackweb.
I've looked closely at the code and it clearly has potential to add attributes, or additional fields, to password nodes in its database. But right now it does not offer this feature for passwords, only for other types of nodes like devices and device categories.