But he is using it for an helicopter?? Yes i saw some projects using the same sparkfun board but they used it in airplanes (and 12 bits ADC), no helicopters, and the system work at 3 volts so the voltage reference is excellent for this IMU, arduino uses 5 volts and the ADC reference is between 0v to 5v, no 0v to 3volts (remeber that the 5DOF uses 3 volts)... Well i obtained a good ADC with 16 bit resolution... an works with I2C... butt i don't know, could work if you only have one or two sensors... but five is too much, i2c is a easy to use port, but is slowly...

Ah maybe the problem with your library's that you cant just copy and paste the code, you need to adapt it to arduino enviroment
Well you can try... but i will give you an advise try to void using arduino for helicopters (maybe for airplane is feasible) but for helicopter you need high refresh rate to maintain it stabilized..

Ok just because i like you i will tell you this:

I recommend you this microcontroller:
http://www.sparkfun.com/commerce/product_info.php?products_id=8559

I can give you the link to download the Keil Uvision for program ARM in C++, and where to buy the JTAG (ULINK2) to program it... This MCU works with 3 volts, ultra low power, you have 3 UART ports (serials), 12 bits ADCs, two I2c, and is 2 dmips of power, that means more or less than 200 arduinos attached together of processing power, and consume the same energy as only one. IS based in the ARM Cortex M3, you know ARM right??? is the microprocessor of all the cellular phones (even iphone), and PS3, etc. etc.

I using it to program my next airplane autopilot and i don't have to worry about power any more and ports.. But you need to read a little bit... and expend some time to get the ARM... but at the END is very easy.. even easier than arduino..

this is what i promise you:

http://cgi.ebay.com/ARM7-Arm9-Keil-ARM-ULINK2-ulink-ME-jtag-usb-emulator_W0QQitemZ260240259693QQihZ016QQcategoryZ73154QQrdZ1QQssPageNameZWD1VQQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247

Work as the ulink2 but is called ulinkme (check it in keil webpage). I used it and is very good.. (was include with my development boards). I also recommend you buy the keil ST32 develiment board because includes the ulinkme free... =)

Sorry im lost.. What reference?