Interesting but in practice is anyone going to be getting their phone out at the pub and recording things?

Don't want to knock a good app, but it kinda seems like a fallacy. If you're sober enough to do be using it then you know how many drinks you've had and approx when. If you're too sloshed to remember what you've drunk then the likelihood of using your phone to record the drink type and time is going to be slim. You'll be talking to people in a bustling environment.

And... who can operate the N900 with one hand (holding a drink with the other) while sober, let alone while drinking!

Maybe it could find a niche for drinking circles/contests; centurions, etc?