Hi.
I am making a presentation in the spanish workshop (http://arduino.cc/forum/index.php/topic,61095.0.html in spanish sorry).
And I want to write about the Arduino's History, something as the boards release date. But I had been searching in the website and internet and I had not found anything.
Bye.
There is some history on the hardware reference page: http://arduino.cc/en/Main/Boards
(For instance, it says that the first manufactured Arduino was the V2 serial, which began manufacturing in 2005.)
And of course the forum archives go back essentially almost forever. Here's the announcement of Arduino 0002: http://arduino.cc/forum/index.php/topic,6691.0.html
I looked at wikipedia and was somewhat surprised to see that they had something of a history, but no dates. They are sometimes a good source for such things. Perhaps once you've pieced the information together, you could update the wikipedia page with the data? Arduino - Wikipedia
The Arduino Documentary can be a good source of information