Content Delivery Network : msny websites use jquery these days.

If all client browsers load this bit of file from central single place, that will save network.

Ideally ... speeds us the page load due to cached file. reduces load on all webservers.

Code to load jQuery Framework from Google CDN
view sourceprint?
 <script  type="text/javascript"
     src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"> 
 </script>
Code to load jQuery Framework from Microsoft CDN
view sourceprint?
 <script  type="text/javascript"
     src="http://ajax.microsoft.com/ajax/jquery/jquery-1.4.2.min.js">
 </script>
Code to load jQuery Framework from jQuery Site(EdgeCast CDN)
view sourceprint?
 <script  type="text/javascript"
     src="http://code.jquery.com/jquery-1.4.2.min.js"> 
 </script>