***NOTE*** This is not a step by step instructable showing you how to make that weird looking thing I made. It's to tell you how you could make any piece of art (or anything I guess) that tweets pictures of its viewers.
This is assuming you know basic C++ and electronics. I used an mbed microcontroller as Arduinos are not capable of compressing a jpeg file and sending it via ethernet. Mbeds us an ARM chip and the software (the compiler) you use it with is on their web page. They cost around sixty dollars and are not that hard to figure out if you've been using arduinos for awhile.
Parts: (All the info on how to hook these parts up is on the mbed page)
mbed microprocesser ($60ish)
RJ45 ethernet jack ($2ish)
RJ45 ethernet breakout board ($1)
LinkSprite JPEG Color Camera ($50ish)
The camera also needed a jumper assembly ...it didn't come with it.
Maxbotix EZ1 range finder ($25ish)
Some wire, solder, and two resistors for the LEDs on the ethernet jack.
(Digital photo frame and steel paper clips are optional)
Here is the C++ code:
A basic mbed program: http://mbed.org/users/treebykooba/programs/TwitPicExample/ln9qdq/docs/main_8cpp_source.html
The twitpic library written by David Griswold: http://mbed.org/users/treebykooba/libraries/TwitPic/ln8r77
Also I used the LinkSprite camera library: http://mbed.org/users/shintamainjp/notebook/camera_ls_y201_en/
(I also used a library for the LCD, for the ethernet and for the range finder...all are on the mbed web page)