Good luck

This one way to do it:

Get another Xbee module and shield exactly the same as the one you have, at least same frequency. I assume you know how to program the Xbee's to communicate, (if not look for an Xbee and Arduino tutorial in the Arduino Playground) Once they are setup on the same ID# and baud rate, connect them as below. Also make sure you put the Arduino board on the PC side in reset mode (connect a wire from the RESET pin to GND).

PC > USB > Arduino(RESET mode) > Shield > Xbee  
-------- WIRELESS ------- Xbee > Shield > Arduino

Your PC will recognize the RESET Arduino with the Xbee as a COM Port. Check your device manager to verify which port it is set to. At this point the COM Port will act just like a cable and all information sent over it will go directly to the other Arduino. (If you set it up properly)

If you run into any problems, which is likely let me know. It took me a couple tries and a lot of reading to get it finally working. I'd be happy to help you through it.

My apologies Good luck mow

About the compile error, I think Arduino requires a setup() and loop() function to initialize. You can leave the setup() empty and use loop() as your main. For example your code may look like this:

#define ....
#define ....

setup()
{
}

loop
{

(Put your main code here)

}

For an "inclinometer" you could try an IMU. ArduIMU is cheap and easy to implement.

Like Mike said, Red is just a dull looking color in general. A lot of the energy being put into the Red LED is wasted in colors that we can't even see such as infrared. To compensate, lower the resistance on the Red. You shouldn't need to increase the resistance on Blue and Green unless you have power consumption concerns.

-Austin

For future reference, Google it first.

The Arduino board is an interface that includes some USB and Serial communication hardware and an oscillator; Basically just a way to easily talk to the main chip, the ATMega328, which is programmed with the Arduino bootloader.

You can get ATMega328 chips with the Arduino bootloader preloaded:

http://www.sparkfun.com/commerce/product_info.php?products_id=9217

plus a 16Mhz crystal or resonator:

http://www.sparkfun.com/commerce/product_info.php?products_id=9420

and you'll have a fully functioning "Arduino". If you need to program it, just plug the chip back into an Arduino duemillinove board and upload the code. Here is the diagram for where you would connect your wires:

http://arduino.cc/en/Hacking/PinMapping168

I hope this helps  
-Austin

It is also called a photo-resistor. Check out this tutorial:

http://robot-overlord.blogspot.com/2009/04/how-to-connect-photoresistors-to.html

-Austin

Error: board not connected

A RTOS would be unimaginably useful for arduino based robotics. Also, error messages should be clearer and understandable. For example I get some crap about a sync error, where my board simply isn't connected. The IDE should be able to distinguish.