Quadrille - 11:49 pm on Apr 18, 2007 (gmt 0)

Buy both and 301 from the 'technically incorrect' to the correct Spanish spelling.

I don't think that Google searches differentiate, though Google.es just might.

People may be 'used to' typing in non-accented terms; but that's not quite the point; the point is, what's their preference? Because you don't want a Spanish site that people think is illiterate, do you? ;)

A bigger issue for you is stopping a rival setting up against you with a potentially very similar name. So buy both.