I'v added a small wireless camera which is attached to a servo. The servo is controlled by the controller board, so that it maintains it's vertical alignment, even if the pitch changes.
This quadrocopter has a serial connection over which it can be configured and monitored (with a program called MikroKopter-Tool ). For recording telemetry data during flight, a wireless serial connection is established between two XBee Series 1 modules .
The XBee module is placed under the bottom left strut of the center plate, below the text "kopter.de".
Since the mosfets that are controlling the brushless motors can genrate a lot of heat loss, i've glued heatsinks to them. The same problem applies to the 7805 voltage regulator, which is replaced by a 3 amps switching regulator. This might cause problems with high-frequency radiation, but i haven't found any disadvantages so far.
This voltage regulator uses a UTC P3596L in a standard circuit as described in the application note.