I use OS X, Linux, Solaris and windows for work and from home. There are good tools that allow me to manage the many logins/passwords required platform independently. But mostly they expect me to carry a thumb-drive around or require direct access to a central location (a sky drive in the cloud).

The thumb-drive is too easily lost (= synchronized backup needed), the central location not always reachable/ mountable. Besides company policy rightly prevents this often.

Is there a tool that allows me to add passwords locally and then syncs it's DB with the "mother-ship" later. Or is there another approach that you use, that solves my problem?

EDIT My question is more about "synchronize" than cross platform. I've evaluated (=read feature list) some good cross platform tools, but need one that does the synchronizing for me. By synchronize I mean "merge two versions" not "replace (hopefully) old file with new." I'm not sure I'm always disciplined/awake enough to prevent data loss.

UPDATE Lifehacker just posted that AgileSolutions now have a beta version of 1Password for Windows.