The latest point release of Leopard is out now, which you can get if you hit up Software Update from your Mac. Updated.
Besides general security fixes, there are Dvorak and Yahoo syncing bug fixes, Widget stability updates, Spotlight network searching for network volumes and some Ethernet Flow Control performance upgrades. There are also improved syncing with Notes in Mail, iCal CalDav support and various other small things. For the full change log, hit up the link. [Apple - Thanks Armyguy19!]
Update: We're hearing that the update is causing some issues with some people. Might want to wait it out a while to see if there's an update to the update. [Apple Support - Thanks Traviscat!]