I ask because I am kind of obsessed with preserving the fragile battery life of the n900. I occasionally use modrana and have to then enable both the these settings. I love that autodisconnect connects my bluetooth and wireless/t-mobile connections after a period of non use, but I don't see any similar setting for the gps/network positioning. So

1) what exactly are the battery implications of leaving gps and positioning on all the time? Are they real drainers or don't use much power?

2) what exactly is positioning? I don't know much about gps but thought gps itself was positioning meaning knows where you are and where you are going.

3) finally, is there a setting or an app that similar to autodisconnect could enable gps/positioning automatically upon trigger of an app such as modrana and disable once the gps application (in this case modrana) was inactive for a period of time or closed?

thanks much for listening...