Hwmayer created a simple oscilloscope python script for the Bus Pirate. The latest version adds triggers, and sampling rates up to 1K using a new command in the upcoming firmware.
Get a Bus Pirate v3b for $30, including worldwide shipping at Seeed Studio. Adafruit also has the Bus Pirate and probe cables in stock and ready to ship.
Via the forum.
wow this is cool! Hats off to hwmayer for his script.