Windows only: Free application Moo0 SystemMonitor places a simple dashboard on your desktop full of system information and real-time graphs covering everything from CPU usage to up time. The lightweight utility comes with a variety of skins to match the feel of your desktop, but other than that there's not all that much to it. You can get similar data embedded directly in your desktop with previously mentioned desktop Swiss Army knife Samurize, but Moo0 SystemMonitor is a simple alternative for folks who don't feel like learning to use an entire desktop customisation tool like Samurize. Moo0 is freeware, Windows only. Mac users, check out previously mentioned iStat Menus.