[cmarshall]

You can use tools in your browser such as FireBug http://getfirebug.com/ or YSlow http://developer.yahoo.com/yslow/ , which will show the time it takes to download each component using your connection.

There's also tools such as this http://tools.pingdom.com/ from Pingdom that'll show the same figures from an independent network link.

From there, look at how long it takes to receive the HTML (not including any of the images, CSS or JS), if that's slow then it's likely that the web server is taking a long time to render the templates server side (it could also be due to a really slow connection...)

If most of the time is spend downloading a lot of images, CSS or JS then YSlow will highlight this and the areas that should be improved. YSlow will also highlight any issues you might have with not setting cache headers correctly.

If the site doesn't contain excessive images, CSS or JS, then the connection might be slow, the 500kb background image will give you a decent indication of the connection speed, though something bigger would be better.

Also, if you have access to the logs then most web frameworks will log out the time taken to render each page on the server.