My PCs got security patches for Java and Mac OS X this past week.
My Windows machine got update 10 straight through the Java Runtime update tool. The release notes are here: http://java.sun.com/j2se/1.5.0/ReleaseNotes.html.
My Macs got two OS security updates and an update to iChat.
Security Update 2006-07 is described here: http://docs.info.apple.com/article.html?artnum=304829.
Security Update 2006-08 is described here: http://docs.info.apple.com/article.html?artnum=304916.
I also got a security update to iChat which updates some certificates. While searching for documentation on this I found it’s caused a bit of speculation with Macworld just around the corner. It doesn’t do much so what’s really the point? Speculation is that it includes features for upcoming products. If I actually used iChat I’d me annoyed if I heard they slipped in some undocumented changes.