I'm trying to come up with an inexpensive vehicle tracking device. I wondering if I can use a Nokia phone hooked up to a 3rd party GPS device to accomplish this.
It seems that a server could send an SMS messages to a Java phone (such as the Nokia 3590) asking, "Where are you?" If the Nokia 3590 were hooked up to a GPS device then hopefully it could respond with an SMS, "I'm at latitude 'x' and longitude 'y'" Is this feasible?
It's not possible with current technology. The Nokia Java phones don't have serial connections that are accessible from Java (Serial, IR, Bluetooth).
Most positioning solutions nowadays are based on network-assisted positioning like E-OTD in US. Server application (or Java application on mobile using server as a proxy) sends a request to locate a mobile. If the privacy settings allow, the GMLC (Gateway Mobile Location Center) server inquires the position from network. Phone send information of three best base stations it can reach. A reference information for the same base stations is acquired from mobile network. Then the location is calculated using triangulation. Accuracy is between 100-500 meters (350 yards - 1/4 mile). All the major US GSM operators are launching such a service as it's mandated by law. You need an E-OTD compatible phone for this service and the operator should allow you to get info from their GMLC, normally for a fee.
The only Nokia phone model available in USA supporting GPS currently is Nokia 9290 Communicator. The GPS is in an optional LAM-1 module, which might not be available (yet?) in US market.
IMHO, I have to say that GPS is of fairly limited use for a mobile phone. They are used mostly in an urban environment, where GPS does have serious limitations, not to even speak of indoor coverage. In urban environment the mobile network assisted (E-OTD) positioning should work much better and should also work indoors most of the time.
There are a few mobile network based location solutions already in use here in Europe, including driving directions ("MAP TO SOME STREET 3"and service locator ("FIND ATM".