Taskbar Meters is described as 'Incredibly simple meters that live in the Windows 7 task bar' and is an app in the System & Hardware category. There are three alternatives to Taskbar Meters for Windows and Mac. The best alternative is Venmon, which is free. Other great apps like Taskbar Meters are TinyResMeter (Free) and Actimeter (Paid).
TinyResMeter is a small tool that displays useful information about system resources in real time, but it also gives much more detail when you right-click on the displayed fields ! Why TinyResMeter ? - It is written 90% at pure API level to keep it as small as possible.
Actimeter is a fun little app that tells you how active you've been at your computer. It tracks and counts all your computer-related activities and events, and turns them into a single, easy-to-understand number from 0 to 100.