Here's what you do:
- Download benzaiten-0.1.tgz and save it to your home folder;
- Open a terminal, and issue the command tar xvzf benzaiten-0.1.tgz;
- cd into the newly created benzaiten-directory;
- Issue the command ./benzaiten
For now it'll only work from the commandline. Also, there's no progress bar to tell you what it is doing -- the first time it will download all your user icons, and that may take quite a while. Keep an eye on the terminal output, because every request will be printed there.
Before you ask: no, Benzaiten does not store your password in plain text.
Anything you see in the interface should work. If you encounter any problems, let me know.