iStat Menus is a tasteful and discreet resource monitor that sits quietly in your Menu bar and monitors all of your Mac's most important components in real time.
The developer of iStat Menus says "we love easy to use, impeccably crafted little applications" and it's hard to argue that iStat Menus is anything but that. The range of information accessible via iStat Menus is very impressive. The temperature sensors in particular cover everything from your AirPort card to battery enclosure, and even power supply. You can switch each individual element on and off via a very easy to use control center.
To see a detailed reading of CPU activity, temperatures and remaining hard drive space, just switch-on one of the iStat Menu monitor symbols in your Menu bar. The only slight downside I found is that, working on a MacBook, the Menu Bar can soon look very cluttered if you activate all of the monitoring features at once. Before long, you have a whole row of monitoring elements taking up the entire bar. There are also no preferences so you can't refine monitoring features according to your needs.
If you want precise temperature readings and performance stats on your Mac, iStat Menus is a comprehensive and incredibly powerful tool.
