There is a very small such tax in the U.K. Fun facts, Bush the first's Secy of the Treasury Brady once proposed one. Larry Summers once endorsed such a tax.
Dean Baker at cepr.net has written a lot about this.
2011/10/27 Ferenc Molnar <ferenc_molnar at hotmail.com>
>
> Darn, if the video led with the elegant and slightly weasely "K-RUG" guy
> who knows how to let the rhymes flow instead of the rather stiff "D.J.
> Moneypenny" I'd be forwarding this video.
>
> But I'm also more than slightly confused about the push for this "Robin
> Hood Tax". It seems to be a variation of the Tobin Tax that groups like
> ATTAC have been supporting. What was originally a tax on currency conversion
> is now, under the Robin Hood Tax, a currency on certain types of financial
> transactions?
>
> And the proceeds of the tax will go to whom? The 50 or so NGO's sponsoring
> the tax?
>
> I'm not vehemently anti-NGO, I definitely believe that some are better than
> others and some are excellent but much of NGO money goes into perpetuating
> the structure of NGO's themselves. And they often, Bono-like, share the same
> bed with the global financial organizations that they are tasked with
> ameliorating. Perhaps it's time to revive the critique of the World Social
> Forums and NGO culture of the mid-2000's... a critique I can barely
> remember.
> ___________________________________
> http://mailman.lbo-talk.org/mailman/listinfo/lbo-talk
>