New E-books

Does anyone know which (if any) of the online e-book stores is most likely to have books on their date of publication?

I only ask because it's only eight days 'til the US edition of The System of the World, and I rather fancy the idea of getting up next Tuesday, downloading it, and going back to bed for the rest of the day ...

If you go down to the beach today ...

... you're sure of a big surprise.

OK, ladymoonray; maybe not Camber this week ...