I just watched the presentation given by Gregg Brockway of http://tripit.com at the Web 2.0 Conference last month on Blip.tv.
There is a part where his phone went off and he said it was his wife. It was really well done (despite the audio folks needing a prod) and having been in similar situations I actually thought his wife was maybe having a baby! Of course it was him demonstrating how simply someone could be directed to use the service on a mobile via email.
It was quite an original way of presenting and demonstrating an idea. Worth taking note.