This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
I believe you have to resort to using proprietary APIs since your cell phone is probably not implementing the Location API, yet. I would start by reading the vendor documentation about any available programming interfaces.