Juan Antonio Rubia Mena tipped us with his DIY logic analyzer based on PIC18F2525 @ 32 Mhz. He writes:
One of the most useful tools for micro-controller design is the logic analyzer. You can find one for every budget or performance, but lately those based in USB connection to PC have gained popularity (not not mention the chinese copies). The main drawback of USB based logic analyzer is the need of using a computer, which uses to be a bit difficult when doing field testing. Digitool isn’t intended to replace a logic analyzer; it’s main purpose is being a quick test tool for microcontroller based development.
Digitool – DIY 4 channel logic analyzer with LCD – [Link]