Another great DVD from Greg that turns the "Over-the-Head" effect into great theatre is Gregory Wilson In Action! Vol. 2; the effect set is called Head Trip and although quite a bit of it requires an assistant, I have done even Glass of Water Over the Head without one. It just takes a little bit of creativity and a great amount of misdirection!
My go-to effect though is generally a flurry-style Spellbound routine. A very quick succession of changes from copper to silver, each a little more visual than the previous and a bit more of a challenge, ending with a Sudbury expansion, and if my Sudbury is not with me, then a complete vanish.
Sometimes in my restaurant work, I take absolutely nothing with me and do everything completely impromptu with borrowed items. As such, I too have used the Glass/Salt Shaker Thru Table but I actually penetrate the coin once before the glass/shaker goes through the table.