simX
Unofficial Mac Genius
Just thought I'd give myself some free publicity here. 
I released Memory Usage Getter 2.0.2 today.
New features include:
auto-refreshing at a user-specified interval
rounding preferences to set how specific the numbers for memory usage are
internal help documentation, including an overview of memory usage on Mac OS X
interface tweaks and bug fixes
You can go to http://homepage.mac.com/simx/ , VersionTracker, or MacUpdate to get it. (For the lazy, here's the direct download URL.)
And yes, for all you freaks out there, it currently runs slowly, because it is using AppleScript as the underlying programming language. 2.0.2 is probably going to be the last version made with AppleScript. If I learn fast enough, I should be able to release an Obj-C version in a few weeks or a few months. No promises on when, though, but it should help with those performance issues, and with the interface.

I released Memory Usage Getter 2.0.2 today.
New features include:
auto-refreshing at a user-specified interval
rounding preferences to set how specific the numbers for memory usage are
internal help documentation, including an overview of memory usage on Mac OS X
interface tweaks and bug fixes
You can go to http://homepage.mac.com/simx/ , VersionTracker, or MacUpdate to get it. (For the lazy, here's the direct download URL.)
And yes, for all you freaks out there, it currently runs slowly, because it is using AppleScript as the underlying programming language. 2.0.2 is probably going to be the last version made with AppleScript. If I learn fast enough, I should be able to release an Obj-C version in a few weeks or a few months. No promises on when, though, but it should help with those performance issues, and with the interface.