Settings:

- 3G always on,
- push-mail with microsoft exchange and nokia messaging with 4 mailboxes constantly connected to the server and waiting for emails
- writing a lot of emails
- displaybrightness at 4
- about 1h music with default media player
- browsing in the internet about 1h with microb

all this combined about 13 hours and still more than 20% of battery left!
so i can't complain