A quick tip I picked up for getting more out of your battery while using a smartphone away from a power source for a day or two. Set the network type to GSM only – ignoring 3G. If you’re not web browsing and are only relying on connectivity to periodically check your email inboxes, then you won’t notice any real difference. But you’ll get extra hours out of your battery!
In Windows Mobile you can do this from:
Start -> Settings -> Phone -> Band – changing the setting from Auto to GSM.
This particularly makes a difference if you’re travelling (like when I’ve been working this week on the train to London), or are in an area where the 3G coverage isn’t great. This is because having your phone repeatedly flick back and forth between using GPRS and UMTS really chews up your battery life.
When you get to where you are going (and are in an area with a decent 3G connection) you can always switch the setting back to UMTS and get the benefits of the faster connection.