For around $30 in parts and a good amount of patience, you can have a completely open source and hackable mp3 player ready to go. It can be modified to accept serial commands, be embedded in an art project, used as the voice of your next smart talking robo-sidekick, or filled with music and used as is. Put in whatever size card you want, up to the theoretical limit of the MMC format.

Your own easy to build high performance logic analyzer for less than 10$.

A lot of tips and inspiration for everyone who wants to make cheap (but nice) laser effects.

Some links to interesting pages with LCD information.

Most used are these green character displays with two or more rows to display menus, status or debug messages. With mass production of mobile phones, color LCDs get that cheap, that they can be used as replacement. To test the display, I hacked a kind of small digital picture frame, that fetches pictures from Flickr.

This project is a short range, infrared and ultrasonic scanner that uses a standard hobby servo to move the sensors and a color LCD screen to display the information from the sensors.

Simple and cheap graphic game system with LCD from Nokia cellphone.

Cheap and excellent MP3 player based on VS1002 MP3 decoder, PIC18F45x microcontroller and LCD display from Nokia 3310 cell phone.