Raspberry Pi driving RC servos through a PIC 16F690 with Face Detection HD

This is a stock Model B Rev 1.0 256Mbyte, 700Hz Raspberry Pi running Raspbian. It is interfaced to a PIC 16F690 through a homebrew 3.3V-5.2V level convertor based on a couple of 2N7000 Mosfets (circuits online). The protocol is I2C, with the Pi acting as master and the PIC as slave. The Pi uses I2C to update 8 registers in the PIC holding angles in the range 0-255, which in turn converts the angles into pulses of 1-2 milliseconds every 20 milliseconds (this is normal for servos). The servos are low-cost generics ordered off Ebay direct from China. The Webcam came from a thrift store and is reported as "Pixart Imaging Inc". The face detection uses the Python bindings to OpenCV and is based on Haar Cascades. The eyes were found in a graveyard. The face detection is slow ... but I only integrated everything this morning, and I am sure I can speed it up a little.