A Multi-Seat Linux Box: This tutorial shows how to build a multi-head, multi-user Linux box using a recent distribution of Linux and standard USB keyboards and mice. Xorg calls this arrangement a "multi-seat" system.
Before you start working with photo images on your computer (or even view them), you should really make sure that your video subsystem is capable and is displaying things correctly. These pages will assist you in adjusting your monitor by providing various test patterns. They also give a brief introduction to issues involved in calibrating a monitor
2.4GHz parabolic mesh dishes from Chinese cookware scoops & a USB WiFi adaptor! Called "WIFRY","WOKFI" or "WOKTENNA" (12"= 300mm diam) shows 12-15dB gain (enough for a LOS range extension to 3-5km)
Weekend Project Podcast: Make simple radios to listen too. These were made with materials that they could get their hands on and were small enough to carry around in a big pocket.
A remote control car that can be driven over the internet or with a laptop wirelessly from up to 500m away. It has a live-feed network camera so that it can be driven without line of sight and a horn so that you can honk at people.
Nice little guide to building an IR transceiver - uses the USB port for stable 5V, but includes a link in the comments to a decent circuit diagram that uses a voltage regulator and therefore doesn't need the USB port for power.
the prototype version of the KeeLogger with full documentation, electrical schematics, and program. Operation of this device is similar to the KeeLogger Pro version, although download is initiated by a special button.
@ Ars Technica by Wayne "Hat Monster" Hardman "The BIOS is that dark, cavernous pathway to your computer's very soul that both beckons and repels the would-be performance seeker."