How to hide from VISITOR that the site is a wordpress site ?

Hi WordPress People,

You know in Twenty Eleven theme, anybody who visits the site can easily find that the site is developed using wordpress .

( Just after the page has been loaded, by clicking ‘ view source ‘ anybody can see the source . in source there may be things like ‘ wp-content/themes/twentyEleven/ …’ bla bla bla ) . So anybody can easily know that the site has been developed using wordpress .

Is there anyway to prevent visitors to know that the site is developed using wordpress ? I mean, I want the visitors to recognize the site as just a PHP site . It’s obvious anybody can view the source of a site using their browser . But some sites I have seen, even by viewing the source code, it’s not possible to find out whether it’s a wordpress site or not .

How they do this ? I mean, can I do this to anytheme ? What should I do ?

Thanks,
Mebox .