I have long been a fan of system monitoring programs, with my favorite being Menu Meters. Menu Meters enjoyed this distinction simply due to once fact, it resided in my menu and a quick glance at the menu bar told me the information I wanted to know. As far as format is concerned, it left a lot to be desired, and iStat pro shined and is a widget I have had from Day 1 on my Tiger installation.
Today, iSlayer, the company behind the iStat pro, iStat nano, and iStat application released a new iStat, iStat Menus, which like Menu Meters, resides in the Menu bar. The functionality is very similar to menu meters, and includes most of the information which can be accessed through the other iStat programs. The functionality is wonderful and the way the information is presented is very appealing to the eye and attractive. My new favorite has arrived. Be sure to check out iStat Menus, the download is free, donations encouraged.