Some interesting things I bookmarked on del.icio.us on April 1st, 2008:

• True industrial design: vintage mic’s - Collection of some beautiful vintage microphones.

• Pocket Piano Arduino Shield - A board for making the Arduino into a portable stand alone music synthesizer. It plugs directly into the Arduino board and provides 25 multiplexed keys (2 full octaves), 4 pots, status LED, reset switch, digital to analog converter IC, and a RCA audio jack.
• FET Preamp Cable - A phantom powered discrete FET (Field Effect Transistor) preamp built into the plug of a guitar cable. It provides almost all the advantages of an on-board preamp with none of the disadvantages.
• Reprap - n. any open-source rapid prototyping machine that can manufacture a significant fraction of its own parts; v.t. (in lower case: to reprap) to make something in a RepRap machine. Arduino was chosen for the next stage of RepRap development.
• Hackers Publish German Minister’s Fingerprint - To demonstrate why using fingerprints to secure passports is a bad idea, the German hacker group Chaos Computer Club has published what it says is the fingerprint of Wolfgang Schauble, Germany's interior minister.