Our Toshiba PDA (e750/755 wife's) have this application called ConfigFree that can detect wifi within area and show some info including SSID, MAC, Channel, Signal Strength, estimate distance and Protected or not. The coolest thing is the app is like an airplane radar where the "airplanes" are the wifi SSID signals circling around. I think it's only compatible with toshiba though.
- Remote Display control, control your PDA from your PC
- Theme Generator v2, make your own theme
- ConverterCE, converts temperature from Celcius - Fahr, weight, speed etc
- Calc98a, calculator
What is the GPS application? I bought Pharos and it's pretty good.