lm_sensors provides essential tools for monitoring the temperatures, voltages, and fans of Linux systems with hardware monitoring devices. It contains a library for sensors access (libsensors), a command-line tool for sensor reporting (sensors), and a daemon (sensord). It also contains scripts for sensor hardware identification and fan speed control.
I-Nex gathers information for hardware components available on your system and displays it using an user interface similar to the popular Windows tool CPU-Z. It can display information for CPU, GPU, Motherboard, Sound, Hard disks, RAM, Network, and USB, as well as some system information like the hostname, Linux distribution and version, Xorg, GCC, and GLX versions, and Linux Kernel. It can also generate a report on which you can select what to include and optionally send the report to a service such as Pastebin (and others). It also features an option to take a screenshot of the I-Nex window directly from the application.
wavemon is a ncurses-based monitor for wireless devices. It allows you to watch the signal and noise levels, packet statistics, device configuration, and network parameters of your wireless network hardware. It has currently only been tested with the Lucent Orinoco series of cards, although it should work (with varying features) with all devices supported by the wireless kernel extensions written by Jean Tourrilhes.
Finnix is a small, self-contained, bootable Linux CD distribution ("LiveCD") for system administrators, based on Debian testing. You can use it to mount and manipulate hard drives and partitions, monitor networks, rebuild boot records, install other operating systems, and much more.