The Fake Lens-Cap Trick
This method was discovered by a reader of this page, to whom all credit is due.
The trick involves acquiring the cap off a 35mm film canister and drilling a small hole, 1/16th of an inch (1.5mm) directly in the centre. In case you are unsure, the film canister is the small round plastic container you put the film in after you have used it ready for developing.
All the caps I have examined have a small indentation right in the centre which you can use as a guide. The one pictured above is grey (to make the image clearer) but a black one will be easy to find.
It just so happens that the 35mm canister lid fits snugly into a 37mm camera filter's female thread and takes on the appearance of a lens cap which allows you to leave the camera filming without looking conspicuous. Shown above is the finished product, mounted in the front of a 37mm Hoya RM90 filter.
The effect is dramatic. As with a traditional camera iris the small hole greatly restricts the level of light entering the lens allowing you to film in daylight using nightshot mode with a fully modified Handycam.
The only disadvantage of this method is that you must operate the zoom lens out sufficiently so that the small circle fills the entire screen. This is a minor inconvenience when considered alongside the effectiveness and low cost of this method.