That only works with the DVX100 and 100A, not the B. As far as I know the trick doesn't work on any other camera. I think any small magnet would work and you just put it next to the LCD.
they started using a plastic piece in the hinge instead of a metal one, so no longer any way to trigger it with a magnet... you;d have to crack open the hinge and trigger it by hand. someone used some kind of switch, but as you know: it voids the warranty.
With every known adapter companies out there coming out with flip modules, the image flip is fast becoming a non-issue. Pricing is considerably less than buying a full fledge monitor.
He's got a good point. A lot of the flip adapters are around the $500-$600 price range and should make this point moot pretty shortly. For those who can't fork that kind of money over and just need to frame shots properly, getting an onboard monitor, even one of the cheapies, is a good option.
Just don't use it to set color or advanced focusing (you can do it but yuo gotta practice a lot just to know when its right). I use a little cheapie Marshall that I got off of ebay for $90 and mount it upside down. I tend to use my larger better quality for focusing and more advanced stuff.