Pageblaster won't speed up initial loading, but it's great for moving around the site.  For initial loading a keep alive service is best.  I use keepaliveforever.com.  At about 10 cents a day, it's tremendous value for money.

I have to revise that. It takes more like 3-5 seconds to load a plain vanilla DNN in its own application pool on a lightly loaded 1.2 GHz server with enough memory, once the application is unloaded from memory. With too little memory, it takes a lot longer. Once loaded to memory, it should respond in or less than a second.

I once wrote a keep-alive app in VB6 that I could post.