Smartphone + 2 (or more) days battery, email, internet etc – My last phone was a Nokia e71. Easily lasted 2 days, and had all the smartphone functionality you caould ever want – WiFi, GPS, bluetooth, mapping, interweb, emails, etc, etc.
Screen is a bit small, but hey ho, it’s always going to be a trade off with battery life. The e72 which replaced it is AFAIK equally good, with some slick revisions.
Blackberry’s IMO are pretty unreliable in comparison (sweeping generalisation – no idea which models are good/bad/ugly). Many friends who have them have done nothing but moan about them. My old e71 was sold on to a mate of mine, and he’s still impressed with it a year on.