I just added a new feature that stores your last.fm login credentials in a cookie (encrypted), so that lastslacker can automatically log you in to last.fm at startup.
I'm working on a greasemonkey script for firefox users (I've never written on before so I have to figure out how they work) that will automatically start lastslacker whenever you visit slacker.com
The combination of these two features means that you never have to do anything but open slacker.com and your last.fm stats will automagically be updated.
New Feature: Auto-Login