The Firefox 3 beta has a nice new UI for remembering passwords. The first time you type a password into a form and click "submit" the browser does the submit and then puts a thin window at the top of the next page asking whether you want to remember the password. In Firefox 2 the option to remember was a modal dialog you had to choose before the submit happened, so there was no way to know whether you were remembering the correct password. By deferring the decision until after the result page loads, you can avoid committing bad passwords.
Firefox 3 is a significant improvement in lots of ways. It's much more responsive on Windows and the new Location bar autocomplete thing is cool. Beta 4 has one terrible bug with scrolling textareas, and the lack of 3.0 compatible addons is a nuisance. But FF3 is generally a big upgrade and stable for use now.