I came across a video earlier purported to be taken in Fremont, Ca on December 5, 2008. The camera has night vision capabilities which greatly enhanced it's field of view. During the first part of the video, you can see a flashing object moving across the camera from right to left. Unfortuantely this is nothing more than an airplane.
But at around 0:20 is when it gets interesting. The camera zooms in onto a boomerang shaped craft that has five lights on it. It's traveling at a much faster speed than the previous metnioned airplane (which is also in the camera's field of view at the same time). It's height can't be that high, as you can see it passing under a few contrails.
My guess is this is a single craft, and not multiple ones. Given the manuevers it performs, it would be near impossible for individual craft to maintain such a formation with little or no variation. Whatever was filmed here is yet more evidence of triangular shaped aircraft flying in the sky. This video has inspired me to aim my night vision to the sky and see if I can capture anything myself. If I do, I'll post it here.