[eluser]pickupman[/eluser]
In addition to the great advice above, and looking at your site, there seems a few ways to figure out the bottleneck. The output class has a lot of great tools for profiling your application. The output class has the ability to place start and end timers. You can put this in your code, and see if there are queries or iterations that are taking too much time. I am in the US, and your site doesn't seem to be loading horrible considering the amount and type of content. Are your caching your tag cloud, as this type of feature on this content could slow things up depending on how it is rendered.
What happens when you save the file to a static page, and open in your browser? Are your resources slowing up page load? I took a look with Firebug + YSlow, and seems like you could benefit from combining your js/css resources. Checkout the carabiner library for CI.
