You can check them all at
http://joaoubaldo.com.
From newest to oldest:
Controlling a bicolor 8×8 LED matrix
http://b.joaoubaldo.com/?p=237Triggering Nikon D80's shutter release with Arduino
http://b.joaoubaldo.com/?p=183My first materialization of an Arduino project
http://b.joaoubaldo.com/?p=154LEDs dancing to the music
http://b.joaoubaldo.com/?p=143Cheers!