I made a "funnel" out of cardboard and I put it into a locking "tupperware" box. You can shake the dice and wiggle them and eventually they will fall into 7 rows of 4d6. Pick the top 3d6 in each row and arrange to taste.
This is not very "old school," but it is the way that my new DM wants to roll up characters. (PS: It's one of my favorite methods too, truth be told.)
Here are some pics --
14, 14, 12, 14, 16, 17, 10 -- not bad...
It's a little fiddly and you do kind of have to wiggle the dice while you are looking at them. I suppose if I made the "hole" a bit larger, the dice might fall into the frame a bit easier and you would be able to roll by "feel."