Pre is my first smartphone, so I haven't had to optimize settings like this before. I'd like to be as accessible as possible without having to recharge every 2 hours.

For Exchange and GMail, is push more efficient than pull? I suspect this is dependent on the rate at which you get mail. During the work week my Exchange account gets mail about every minute. GMail is maybe 5 mails a day. Does the answer change if you're on wifi vs. mobile? (How does Push work? If the phone has to keep an open connection with the server I would think that could be very power hungry).

Does staying 'Available' in GoogleTalk drain battery? I have about 1 or 2 chats a day.

Any advice would be appreciated. Thanks.