I'd like to develop some software for GPS-enabled mobile phones.  I'm
having a heck of a time understanding what carriers/phones/platforms
support GPS and GPS apps TODAY, and separating the hype from the
reality.

I see Sprint/Nextel/Boost phones talking about GPS prominently, and I
hear that Treo's hve GPS chipsets but they are difficult to access
somehow...  I'm quite thoroughly confused.

Where can I go to learn about the world of GPS phone development TODAY
and TOMORROW (not vision pieces from 2003)?  Thanks for any help
getting me oriented!

firstly get away from the carriers because its the phone manufacters
who build in gps. Dont get it confused with gprs. Basically some
people are making phones with a gps reciever built in however since
this is still new there is no set standard. My advice to you would be
to select a single maker that makes a few popular gps phones and
search for information about their specific chip. This should allow
you to create a program that will run on those phones and with luck
future phones by that manufacter. Unfortunately its more an issue of
the system running on the phone that will stop it being universally
acceptable.