iStat Pro
All my Windows geek friends have nifty taskbar software that indicates the temperature of the CPU and other useless but interesting geek information about their systems.
iStat Pro is cooler than any of the tools they have. Developed as a dashboard widget, iStat Pro displays CPU temperature and fan speed, but also duplicates all the information in Activity Monitor, displaying typical geek Unix system info, like active processes, memory usage, and so on.
All in a dashboard widget, and all for free (donationware)!

January 31st, 2007 at 7:57 am
Oh man, I didn’t notice that it had upgraded. That looks snazzier than the version I have. When my fans get going, I like to pull it up and be like, wow, I better get ventilated!
January 31st, 2007 at 11:14 am
Lol! Cool. With my Mac Mini, I’ll look at the fan RPMs and wonder, “What? The fans are on?” If it weren’t for this widget, I would’ve wondered if they ever turned on.
I find it most handy for tracking my RAM. I’ve discovered that I am extremely low on RAM when doing even mundane tasks. Sure, Activity Viewer shows this info, but it’s so much handier to track as a widget. Anyway, seeing the low RAM makes me wonder how often my Mac Mini is bogging down just because of RAM, the poor little guy.
Also, have you noticed that the CPU usage appears to report as a single core? I’m assuming that’s what is happening, because I’ve seen processes reported as running at over 100%.