WARNING: None of this is something that the FAA condones and may be
downright illegal. If the ship is "experimental" then you may have
more leeway.

A few comments;

1) The AV industry always use "gaffers" tape to affix things. This
stuff is very good at keeping things stuck while still coming off
cleanly. Think of this as really good cloth "duct" tape with a price
to match.
2) Most external cameras I now see being used are "lipstick" cameras
which are very small and have a much lower wind loading. These are
small enough to be directly taped to the wing, tail, etc. They also
have smaller lenses so they are less likely to get a bug in the face.
They have video out so a cable must be routed back into the cockpit to
a device to record the video.
3) Non-lipstick cameras have also been used. The advantage is that
they are self contained cameras plus recorders. Anchoring is
typically done by using a large-ish aluminum plate which wraps around
the leading edge (wing or tail) and is held in place with gaffers
tape.
4) Asymetrical wind loading by putting a large camera way out on a
wing tip is something to avoid.
5) Don't' do this if there is even a hint of rain as this will distroy
the camera in a hurry.

- John