"This is pre-alpha quality software, the result of a three
day project. It will crash your browser, leak your
passwords and destroy your home. This is actually my first
Chrome extension and I am no expert javascript programmer."
For Safari (and Chrome) I made a little automator service that gets the url from the browser, strips the hostname, then feeds that into a shell script that calls pass and puts the password in the clipboard for 45 seconds.
It actually works better (for me) than 1password which was always a little flaky at recognizing a website after any kind of site update.
passwordstore just (with my distro) starting shipping a dmenu (http://tools.suckless.org/dmenu/) script that I think is great, and personally removes the need for a browser extension. Unfortunately only available on linux.