MacKenzie mentioned one of these in her latest post and while I’ve linked it there, I always like to promote it a bit more.
Firstly, though, another speech that I read before:
Steve Jobs’s Commencement Address at Stanford: Stay Hungry, Stay Foolish (text)
Video of this on Youtube
And finally, the best one of all:
(If that link doesn’t work, try this one.)
It’s 100 minutes long but well worth watching.