i like the ring light solution on DSLR, it is very light on the lens, qui to setup, and generate no shadow.
i built them from "angel eyes" you can buy for very cheap on ebay.
they exist in several sizes and you can easily glue 2 or 3 together depending the amount of light needed.
for few dollars more you can add a little box for intensity control.
i used a UV filter (glass removed) to allow to screw the ring directly on my lens.
a 3$ plastic AA battery holder is enough to give you light for hours.
i will provide a picture asap.

Would love to see it :)

For the record, depending on the banquet facility I may use a light stand, i may use an on-camera light or I may just use available light. I find that each banquet hall is different when it comes to their lighting situation. I really hate using an on camera light, but sometimes I find that it is necessary. It was necessary this past weekend because the hall was colored like a disco with flashing colored lights. My on camera light brought out the whites without ruining the ambiance of the wedding. If I didn't use an on camera light, everyone would have appeared blue or pink. So I don't believe there is really one good answer when it comes to lighting. The video is important, but so is the ambiance of the event and we as professionals have to respect that.