title: What will be the fastest way to implement a good search on my site?
body: <p>Say I have a site like stackoverflow. I need to add a search functionality, I need it to be good. I don't care if I have to add a logo (like if I am using a google search). 
  What options do I have, with minimum of development and minimum server type dependency.<br>
  I am currently on Lamp (php).  </p>
  
  <p>EDIT:<br>
  Pardon, but I am talking about an open source application, which each user is installing on his server-machine (hence the requirement of not server specific). The goolge search, as far as I can see, I have to subscribe to it first, A process I wish users not have to do.</p>