Extend WP7 battery life

I am going to a 4 day music festival next week bringing my WP7 Samsung Omnia Phone and I need to save as much battery life as I can, while still being able to SMS and phone.

Last your I brought a HTC Hero Android and that didn't last more than a day and a half without a recharge. 

I am in the process of figuring out what to disable and I think I am on the right track. I changed the settings 8 hours ago.  I have send 20 SMS messages and been on the phone for 1 ½ hour and the battery is around 90 % full.  So it looks pretty good for WP7 on this one

Current settings:
Turned off Bluetooth, WiFi, Data, 3G, GPS (Location)
Screen Brightness: turned auto brightness off and set brightness to low
Switch team to brown. Should save power because black will be the primary color present.
Set screen time-out to 30

Anything else you can think off and what is reason for that WP7 seems to consume less power than the Android?  

@fabian: I think turning of "Connect to XBox LIVE" under the games settings also helps.  I believe it polls the XBox Live servers for requests for the live tile.  That is all I can think of at the moment... 

What about buying one or two extra batteries? It's not an iPhone, you know...

@fabian:

1 hour ago, fabian wrote

Anything else you can think off and what is reason for that WP7 seems to consume less power than the Android?  

Better power management and no rogue background apps.

1 hour ago, fabian wrote

I am going to a 4 day music festival next week bringing my WP7 Samsung Omnia Phone and I need to save as much battery life as I can, while still being able to SMS and phone.

Last your I brought a HTC Hero Android and that didn't last more than a day and a half without a recharge. 

HTC is notorious for using tiny batteries in their phones. The HTC HD7 has a 4.3" display but has a 1230 mAh battery. Most Samsung phones have at least 1500 mAh batteries.

@PaoloM: Or some kind of portable charger. I have a couple from Tekkeon that work pretty well.

Going to a music festival = TURN YOUR PHONE OFF
People are there to hear the music, not your phone ringing.

http://www.solio.com/chargers/