HTC Evo - Can Wi-Fi Radio Sleep? I've noticed that when actively downloading a lot of data, the Wi-Fi radio uses much less power than the 3G radio.  However, when the phone is not being used much, the 3G radio will sleep but the Wi-Fi radio will not.  This actually means that if I leave Wi-Fi on, my battery will drain about 2.5 times faster than if I were using 3G.

Is there a way to get the best of both worlds?  When in range of a Wi-Fi signal I'd like it if I could leave Wi-Fi on and it would sleep in a similar manner to the 3G radio.  Is this possible?

Settings > Wireless &amp; networks > Wi-Fi settings > Menu > Advanced > Wi-Fi sleep policy > After 15 min
doesn't appear to do what I want.  Basically, Wi-Fi will always be on and then if not used, will turn off after 15 minutes and turn on the 3G radio.  And then the 3G radio won't sleep at all!  Which is really horrible and not what I want at all.
Presuming that you normally only want your Wi-Fi switched on in certain locations (e.g. Home and Work), then an app like Locale that can change profiles and switch power-hungry components like Wi-Fi on and off based on your location might do the trick for you?

(note that this is not a free app)