Connection time out port:80

Well.....I really wanna know what cause the connection time out and why? and how we can fix it? Besides, what does the port:80 mean? I really need somebody who is good at networking to help me with this or at least teach me something. Because this is what happens when I clicked on the megaupload link to download stuff or even upload stuff. It always ended up with connection time out port:80. My ISP is qwest. And I have contacted them for support for more than five times. But none of them could help and solve the problem. They just said sorry and then they claimed they couldn't do anything about it. But it works fine with other broadband service.