http://www.islayer.com/apps/istatmenus/

Does most of what Hardware Monitor, Temperature Monitor, MenuMeters and MenuCalendarClock iCal do, but in just one app : mini calendar, memory, disk, network and cpu usage, fan speed and power consumption, tempratures and much more!
Easy to install and configure, excellent design, like always from islayer.

Screenie:

And yes, I configured it to look like MenuMeters…