Procyon MP3 Player
Another homebrew MP3 project from awhile back…Procyon MP3 is a hardware MPEG 1 Layer 3 (MP3) audio player which supports user-controlled playback of MP3 files stored on a typical IDE hard disk connected to the device. With the emergence of MP3 as a popular standard for storing, playing, and exchanging music, droves of electronics and computer companies have introduced both portable and desktop MP3 player devices into the consumer market. The rise of MP3 has also produced dozens of personal engineering projects like this one. Link.
Tonepad is dedicated to providing ready-to-use layouts for effects and amplifier projects to the do-it-yourself music community. All layouts are provided free of charge and are subject to the limitations set forth on our legal page. Parts are available from Small Bear Electronics, and ready-made PCBs for many projects are now available directly through tonepad. 
Qucs is an integrated circuit simulator which means you are able to setup a circuit with a graphical user interface (GUI) and simulate the large-signal, small-signal and noise behaviour of the circuit. After that simulation has finished you can view the simulation results on a presentation page or window. The software aims to support all kinds of circuit simulation types, e.g. DC, AC, S-parameter, Harmonic Balance analysis, noise analysis, etc. 
Good for a ton of projects that use video. This simple adapter can be used to convert Y/C video (S-video) to a composite video. This adapter is useful in cases where your video output device has only S-video output but your signal source accepts only composite video input. This circuit works with both PAL and NTSC video standards. 
Do you like the idea of tesla coils and other high-voltage sparking stuff, but don’t have the time, money or patience to build something that elaborate? Here’s a fun little project that can make big, fat, noisy sparks at least 2 inches long, and can be built very quickly and cheaply. The Marx generator consists of an array of resistors, capacitors and spark gaps. 
Lots of MP3 players as final projects- schematics and source included. Our goal was to design a scaled down version of an otherwise marketable product with minimal cost. Our intent was to ensure that our end result would be expandable to include all of the functionality of the most popular players on the market. 
Here’s a good resource for making an cell phone LCD in to a small display that gets its data from the parallel port. pcd8544-based displays can be found in some monochrome nokia-cellphones. With some technical skills, an independant, small display with background light can be gained out of these phones at hardly any costs.