HOW TO – Make a Digital Pinhole Lens
“One of the oldest camera forms is the Pin-hole, or “natural” camera. The pinhole camera was mentioned as early as Leonardo DaVinci in his Codex Atlanticus and Manuscript D. The term Camera Obscura or “dark room” was first used by Johannes Kepler who used the term to describe a dark room or box with a small hole used by artists to draw landscapes, it wasn’t until the 1850’s that the first photographic pinhole image was created.” Here’s how to make one for you digital camera. Thanks Greg! Link.
“One of the cooler lighting effects that we have left over from the 90’s era fashion photography is the use of Ring Flash as a primary light source. Ring flashes are often used in either fashion photography or in macro photography where the ring of light helps to eliminate shadows. When used in fashion or generally people photography it has the effect of creating a flat but almost iridescent lighting quality with a ‘halo’ effect around the subject. Cool yes, cheap? No. Flashes designed for macro photography generally will set you back about $400, while ring flashes for medium format and intended for fashion photography cost well over $1000!…Well fortunately, building your own ring flash is a fairly easy project with results that can easily rival professional ring flash assemblies for only a fraction of the price.” 
Nick writes “Here’s a great collection of homemade musical instruments and instrument mods from Dennis Havlena. Most are cheap and quick, and include sound samples. I particularly dug the simplified hurdy-gurdy.” 
Diy.sometemple writes “This is an extensive collection of automated and programmable musical instruments designed by the logos foundation. There are lots of photos and wiring schematics and the like. You can get lost on this site for hours.” 
“These transit tokens from New York were discontinued in 1980 and have now been recycled into cuff links, courtesy of their designer Ward Wallau. He spent 11 years petitioning the NY Transit Authority before they finally gave him permission to use them in his jewelry, making them truly special. These unique cuff links are also available with recycled transit tokens from Boston, D.C., San Francisco and Chicago.” These might be fun to make, perhaps out of arcade tokens… 
If you have some old CPUs laying around, you can turn them in to great geeky keychains, perfect for holiday gifts. The process is pretty simple, drill a hole, get a keyring and that’s about it. 