How often (on average) are the Google databases updated? I've got revised content that isn't being picked up in a Google search. The Webmaster tool says they last crawled my site on 27th July - is there any way to 'force' an update?
Over time Google reacts to how often your site is updated - if it finds new content every time it crawls, then the frequency with which it returns picks up.
sitemap and more backlinks from high PR sites will allow bot to visit your site more often and your content will be refreshed too. good place is put your site link in your signature in DP will help.
google webmaster tool was kinda late in update lately... putting your link on fast-crawled site will get you crawled within a day... don't force it just do the right way...
My site ( http://www.healthgenie.org ) is not still crawled by google bot since launch a week ago. My site map has changed lot many times since then and every time I changed it, I have resubmited it to google. Still no result., no crawling!!