2 by the dock connector on the outside

8 in the logic board

2 for the vibrator

2 for the lock button

4 for the volume/vibrate buttons

4 for the headphone jack assembly

1 for the SIM card ejector

3 for the dock connector assembly

6 (I think) in the screen assembly

=32

Be careful, they're different lengths, some aren't threaded all the way to the head, etc. Should have kept track of where each went, but good luck.