I'm wearing these shoes today, and I CANNOT walk in them, because they are 1/2 a size too big. What can I do in a quick fix (I'm at work) ?
well, ideally, you should use some of those adhesive pads that go under the ball of your foot - they keep your foot from sliding around.
since you probably don't have any adhesive foam lying around (or maybe you do?) do you have any soft packing foam around and some 2 sided tape?
ETA: cute shoes!
If you have a first-aid kit around, put plasters/bandaids on the "ball" area of the shoe. cloth is preferable over plastic.