Secure Login is a FireFox extension that adds similar functionality as Opera’s Wand has. Basically by clicking on the "key button" (or using keyboard shortcut), Secure Login fills the login fields with the saved password data and logs you in. There were some news last week about a "hole" in FireFox that let’s malicious sites to steal saved passwords (read more here). Secure Login "fixes" that issue by not filling the login field until the user tells it to do so.

Secure Login
https://addons.mozilla.org/en-US/firefox/addon/4429

found via Lifehacker