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.
fairly simple DTMF decoder to control solenoid door unlocker and connected it to phone (in this case a cell phone). NOTE:CALLERID would save the phonecall as commented on the article
is short for Replicating Rapid-prototyper. It is a practical self-copying. Complete open-source instructions and plans are published on this website for zero cost and available to everyone so, if you want to make one yourself
MIT professor Neil Gershenfeld talks about his Fab Lab -- a low-cost lab that lets people build things they need using digital and analog tools. It's a simple idea with powerful results:
a small device which plugs into a $20 prepaid mobile phone to make a GPS tracker. The Tracker responds to text message commands, detects motion, and sends you its exact position, ready for Google Maps or your mapping software
So how to combat with all those difficulties and save your time on these cleaning tasks? Do It Yourself.com has some (well over 150) tips, tricks and how-to on cleaning stains, items and rooms.
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.