With the surge of cell phone apps for iphone, android, palm pre, there are a lot of different things that you can do, but require an accurate location.<p>Before starting the actual development for an Android app, I assumed that GPS is reliable and fast. I have since found out that there are major issues to get an accurate location (like it usually takes a minute or two to find the first location, and in certain places it doesn't work that well).<p>I've read the explanation for how gps is supposed to work, but is there a good manual for how it works in the wild? Stuff I'm curious about:<p>- how do you increase the accuracy, decrease the time? trade offs between constant polling / battery life, etc.
- how do AGPS, differential GPS, enhanced GPS, and other assistive GPS technologies compare, (including cost, if necessary)
- what are the alternatives, and how well they work (is it possible to do triangulation from cell phone towers?), use wifi information?