My most recent project: Sharkuino: Controlling an Air Swimmers shark from an Arduino.
I build my Arduino software from the command line -- the page contains a Makefile and instructions.
A couple of little Arduino hacks I thought might be worth sharing:
sonarduino, to send audio pings according to the output from a sonar rangefinder; blogged here: Sonar / Echolocation with an Arduino.
You can also just monitor and test the output of the rangefinger (or any simple
single-wire analog sensor) over USB (as demoed in the talk) with this sketch:
rangefinder.pde.
I always start with that when testing a new device to get an idea of range
(how high and low do the numbers go?) to calibrate a new sensor.
battimer.pde, code for a battery timer that gives audio alerts warning you how close you are to the preset timeout. I use it when flying R/C planes, so I don't fly too long and destroy the plane's batteries.
scopino is the beginnings of an oscilloscope program, similar to Arduinoscope.
ardmonitor: a Python script to monitor the serial line to the Arduino, and even send commands back to it. Blogged here: Monitor an Arduino's serial output from Python.