Helsinki City Transport offers service, where the current position of every bus is being displayed online. Each bus has a GPS delivering position specific data. The information is shown in real time on Google maps. There are official maps owned by the government that are fare more detailled . In such cases it would make sense to (re)use resources that have been payed via taxes already by the citizens.
WW2D  is cross-platform, free and open-source application similar to NASA World Wind or Google Earth software. WW2D allows you to explore Earth using satellite imagery, topographic maps and image from other data sources also providing large placenames and boundaries database and allowing you to install community-made add-ons for even more information about our planet.
Mobile GMaps is a free piece of software that displays Google Maps and MSN Virtual Earth maps and satellite imagery on Java J2ME-enabled mobile phones or other devices.
Mobile GMaps is distributed under the Attribution/NonCommercial/NoDerivs Creative Commons license. You may download, use and distribute the application free of charge for non-commercial purposes. You may NOT use it for any commercial purpose.
Have a look at the documentation to see what phones are supported.
Siemens bringt mit dem SXG75  nun auch ein Mobilephone auf den Markt, das gleichzeitig als Navigationsinstrument dient. Im Vergleich zum Nokia GPS-Shell ist das GPS beim SXG75 direkt integriert. Erhältlich soll es ab Oktober 2005 sein.
randy  found a way to get the longitude and latidue out of an address like "1600 Amphitheatre Parkway, Mountain View CA 94043". He uses an XML-RPC call to rpc.geocoder.us and gets an array of mapping coordinates in return. Awesome.
As the current petrol prices are rising, I would like to see an SMS service, where you can send something like "Lorraine, Bern" to a certain number and in return you would get an MMS with a map with a red outlined track to the next petrol station with the lowest prices on petrol. ;)
You haven't used the Launcher to log on, therefore you are "plazeless". You cannot search for people or Plazes by radius.
Apart from binaries there is also a Python launcher . That is ok, if Python works on your system. So I was looking around for a signed Java Applet which gets access to the machines MAC address . I am not sure, if at all, a launcher is programmable as signed Java Applet , but it would be fun to have a platform independent Launcher anyway. Maybe there will even be a non-Java Plazes Launcher Firefox extension one day, but that is just a guess.
For a Nokia 5140i you can get an Xpress-on GPS shell . I have seen it working a week ago. Unfortunately the Nokia 5140i is no Python phone - as far as I know. So to add the GPS data to an MMS is still not solved I guess and a quick Python hack out of sight. Has anyone successfully sent an MMS and the appropriate geodata with a Nokia 5140i phone?
Christopher Schmidt  seems to have implemented, what we recently discussed  at a bloggermeeting. As Chris writes:
One of the benefits of having the ability to work with the phone is that there is an interface to the cell tower you are connected to. With this information, it's easy to make a "Where I've Been" type of interface. This is one of the first projects I did when I got the phone: The output of my wandering can be seen, although it's very incomplete due to limitations of the program.
I wrote down an idea of refinig the "cell tower position" via a look-up table [3,4], where the position of each tower will be determined with a GPS. But Chris script is a good start giving a reasonable resolution already.