Hi all My wordpress blog uses xxxx/?p=6 model to link to a post. Does google like this kind of linking? wouldnt it be better to use Apache's modrewrite to toogle it to xxxx/6/ ?? Or are both the same?
Those links are fine in Google...I've got a blog set up that way that does pretty well on Google SERPs. But for SEO it's better to use the alternative "date and name based" permalink structure, which you can choose at xxxx/wp-admin/options-permalink.php of your blog site. You'll need to be able to set up an .htaccess file to make it work, though, because it does use mod_rewrite.
I would suggest you to rewrite the URL's. Though google is able to crawl dynamic links but still a static link is always better any day of the week.