I've used this adapter,
The adapter suports the SPP profile. you can probably find it cheaper on eBay. Basically you just open a COM port on the Netduino and talk to it with whatever serial App you have on your Android device.
If you want to develop your own Android App, I have found that Basic4Android is absolutely the easiest way,
The syntax is pretty much like VB Net and for a list of libraries,
thanks so much for your suggestions, they are really helpful.
I'm a big fan of sparkfun, so i'm planning on using the WRL-10269 BlueSMiRF Silver (https://www.sparkfun.../products/10269)
I'm comfortable using eclipe and doing the programming in Java; I took the tutorials offered for free by Marakana; here is a link to there android bootcamp:
What I was hoping for, was someone having put together an open source library that does all the dirty work of communicating between the two devices and manages different data types (i.e. string, int, float, byte, etc....)
Bluetooth comms on Android is not fun