Always have wifi - Free!*

* If you're on Android

After switching from my Nexus One on T-mobile to the Evo 4G on Sprint, due to poor 3G coverage in my area with TMO, I started experimenting with wifi-tethering on my rooted device.  Tethering allows you to use your phone's data connection on your laptop via wifi.  It's a wireless hotspot in your pocket.  

After trying this, I initially would getting disconnects after 5 mins or so, and I think I finally found out why:  Locale.  The location and time based settings manager regularly polls GPS and wifi to figure out where you are, and adjust your settings.  While tethering, it would poll my location, then turn wifi on and off (which I was using for my data connection).  I'm testing this theory now, and if it is true, I'm thinking of working with the devs of the wifi-tether app to see if they could build something into their app to temporality turn off locale while tethered.  

If you're any android user, I recommend rooting your device and tethering.  The carriers charge for this "privilege", but with Android, you can do it yourself and save the 20-30 bucks a month.  Take that iPhone users.

Link to the tether app: http://code.google.com/p/android-wifi-tether/

UPDATE 7/22/10:  Looks like that did the trick, no more disconnects.  Woo!