One more.
You don't need R7. All the pins have internal pullup resistors:
pinMode(pinX, INPUT);
digitalWrite(pinX, HIGH); // turns on the pullup
Put 100nF caps from Vcc/Vdd and to Gnd on all devices (and some would suggest at the SD card also).
Put a 100nF in series from X2-4 to the reset line, will allow DTR on an FTDI Basic or similar to create a reset during programming.
Put a diode across the pullup resistor, somehow there is some noise generated or something when reset is toggled that can interfere with smooth programming, see the latest arduino designs.
Add one pin to X2 and change the order to:
GND-GND-5V-Rx-Tx-DTR
so an FTDI Basic or equivalent cable can be plugged right on.
Same with you ICSP, you seem to have room, make it a 2x3 header with pins:
MISO - 5V
SCK - MOSI
Reset - GND
to accept a standard 6-pin ICSP programming cable.
Having to come with adapter cables is a pain in the butt.
With 150 ohm resistor your power LED will be Really bright - maybe tone that one down some?
(5 - Vf-led)/150 = mA.
Vf-led - 2V?
(5-2)/150 = 20mA
ITG-3200 is not wired like the Typical application in the data sheet
http://invensense.com/mems/gyro/documents/PS-ITG-3200-00-01.4.pdf
Check your capacitor connections.
"The LSB of the of the I2C slave address is set by pin 9 (AD0)."
I would connect this pin hi or low, not leave it floating.
You are not monitoring the Interrupt line?
"Items that can trigger an interrupt are (1) Clock generator locked to new reference oscillator (used when switching clock sources); and (2) new data is available to be read from the Data registers. The interrupt status can be read from the Interrupt Status register."
I would think #2 would be important. You have IO pins free, connect it up, you can always ignore it.
Check the wiring for Vss on ADXL345.
"A 1 ?F tantalum capacitor (CS) at VS and a 0.1 ?F ceramic capacitor (CI/O) at VDD I/O placed close to the ADXL345 supply pins is recommended to adequately decouple the accelerometer from noise on the power supply."
"It is recommended that VS and VDD I/O be separate supplies to minimize digital clocking noise on the VS supply. If this is not possible, additional filtering of the supplies, as previously mentioned, may be necessary."
Wire up the INT pins - same logic, you can always ignore them. Hard to add in after the fact.
