For me, when I covered the EPL Ice hockey playoffs in a live podcast from outside of the Coventry Ice Dome. I had a chatroom running, was posting to the clubs' forums and was updating the links on Facebook at the same time.
Moreover, all of this was over HSDPA and not wifi.
I then went back to the hotel and stuck a movie on using the standard TV Out connector.
I did have to do one battery change during the day but mate had his N900 with him and so I used his battery in my phone.
It was a good N900 day.

EDIT: www.phoenix-podcast.co.uk for those who are interested.