I just write my passwords into a plain text file, or an RTF file and name it something very obscure, such as XPF10GH5.ZXH. If you want to hide it in the finder, put a "." in front of the name such as .XPF10GH5.ZXH. Now you can override the defaults in the Finder IF you know how to in the command line where every file is visible. I then bury the file many folders deep somewhere in my user directory. If you want, create some dummy files with similar names that have other information that may be useful to you. Just keep track of which files are which. If you're so inclined, look up a Mac OS X system file name, and change it slightly, like mispelling it for your intended file. The possibilities are endless, and no one will go rummaging through your computer looking for files with obscure letters like "XPF...", someone is more likely to search for words that MEAN something to you.
The problem with using some weird piece of software JUST to keep track of your passwords might not work with an Apple system software update. What do you do then? Wait for the author to update that software? I don't like depending on software that specific for something so critical to my internet experience. If you're a microsoft slave, you can always password protect a Word file that has some weak encryption algorythm. But then again, you're tied to M$.