These two video clips are part of a documentary from ABC, the complete version of which is here. They are both hand held camera shots, taken from quite close to the collapse. The first one is taken from the east and a little north of WTC-2 and catches the collapse from very close to the onset. The explosive nature of the collapse is painfully obvious as debris is ejected at high velocity laterally, even in the earliest moments.
Click picture for MPEG, here for AVI
The second clip is taken from the opposite side, northeast of the South Tower. Notice how remarkably uniform the sheets of dust and debris are as the advancing collapse moves down the building. Despite the fact that the South Tower collapse began with the top section tipping to the south and east the collapse moves in a flat horizontal sheet showing almost perfect symmetry.
Click picture for MPEG, here for AVI
Notice the shadowed bulge appearing about twenty floors below the demolition wave. This is the beginning of an isolated explosion, one of the squibs that can be seen at several levels in the North Tower collapse, for example here and here.