iStat Menus

iStat Menus screenshots

Monitor the performance of your system directly from your Menu Bar.
iStat Menus 6.0 : Welcome Window

Alternative downloads

MenuBar Stats
Monitors your system and signals what does not function well.
Memory Usage Getter
Program which graphically shows the memory.
Launch! Usage Meter 5
Launch! Usage Meter displays usage statistics on the BigPond broadband network.