SpeedFan - Hardware monitor for Windows that can access digital temperature sensors located on several 2-wire SMBus Serial Bus. Can access voltages and fan speeds and control fan speeds. Includes technical articles and docs.
lsscsi - Uses information in sysfs (Linux kernels 2.6.
Open Hardware Monitor - Monitors temperature sensors, fan speeds, voltages, load and clock speeds, with optional graph.
cpuid - cpuid dumps detailed information about the CPU(s) gathered from the CPUID instruction, and also...
xScan - xScan is an application for viewing the behavior of your computer and Mac.
Speccy - Speccy - find the details of your computer's specs. Great for spotting issues or finding compatible upgrades. Download the latest version free.