Weather on Demand is one of the most common applications of SMS. Few of weather service examples are:
1. Weather alerts from Verizon .
2. Weather Network and TELUS Mobility's On Demand Weather service and
3. Weather.com's Radar on Mobile Phones.
With a simple MIDlet you can get Weather forcasts free on your phone. US government provides free weather forecasts here. Note that the weather forecasts are not as high quality as commercial services. The simple MIDlet here displays weather at SF(modify the URL to point to your city):
You can download Weather.jar and Weather.jad directly. Tested on my i88s. Here is the screen snapshot of Motorola i88s simulator:
This can be further extended to support features like:
1. Select the city where you want weather forcast(using kxml)
2. If your phone supports GPS( like my Motorola i88s), you can display weather forecasts for your current location.