All Firefox users whether you're still using the old 2.x branch or have moved on to the new 3.x series, Mozilla has new updates available for you today. The company has released Firefox 2.0.0.18 and Firefox 3.0.4, primarily to include some new security updates.
Firefox 3 has received at least eight security updates, along with a "stability" update and a small scattering of new features, though none of them particularly exciting. Meanwhile, Firefox 2 received even more fixes, totalling 10 security updates among the scattering of other improvements as well. If you haven't been automatically updated already, grab the update when you can.