When I was about 10 years old, I made a huge Lego stadium. I'm not joking you either when I say that I even had advertisements. I remember it very well, I was bored one day so I just started building it. Before I new it I was huge and took up a big part of my living room. During the off-season I even used to change it into a hockey arena with a scoreboards hanging over center ice. It's too bad that it isn't assembled anymore, I would have taken pictures and posted them.
Very impressive stadiums! Please check out my Lego Miller Park Baseball Stadium. I've been working on it on and off since 2001 and it's equipped with a motorized retractable roof! You can check out my current version at http://mocpages.com/home.php/7457. Where is the "Allianz Arena" located??
Missed this thread until Loney highlighted it in his newest blog entry. That first soccer stadium under Fenway in the original post is mine. Its packed up at the moment, awaiting a larger area for it to be rebuilt. Once the area is found I'll be remodeling it into a replica of Dick's Sporting Goods Park.