When I use Jquery or its plugin, should I just add 

```
<script type="text/javascript" src="http://code.jquery.com/jquery-latest.js"></script> 
<script type="text/javascript" src="http://dev.jquery.com/view/trunk/plugins/validate/jquery.validate.js"></script>

```

Or should I download both files and upload both to my web server so my web server can fetch both files locally? Which is better and why?