I've used this before and probably posted about it but since I used it I thought I'd just comment on it again.

A LOT of mention is made about modifiers, softboxes, umbrellas, all kinds of fancy stuff to light scenes...but this technique works great when you just want to get 'er done.

You can use this technique by putting two speedlights up in opposite corners of a room, shooting them into the upper corner and you will have even soft light to shoot parties, get togethers of any time where you don't want to flash people in the face or set up light stands.

If you keep the strobes on low power, and mix ambient, after a few minutes folks won't even realize that flashes are going off up in the corners of the room!

So here is the shot, and here is a shot of the set up...a YBN560 just sitting on my entertainment center. (I only used one but you can use two or more.)

My walls aren't even white...they are a puke yellow for the most part so this is a pretty forgiving technique on that count.

Also note that this helps you keep depth of field and image quality because you don't have to open up wide and use a high ISO...you are raising the light level to an acceptable level without making it look "flashy".