It is true that there are easier places to do a mileage run, but the usual ones in Asia are pretty sterile compared to Beijing. Getting the visa is pretty easy. Will cost you about $35 plus handling fees.

Taxis to/fr the airport are a cinch. No problem, even if you don't speak any Mandarin. It would be wise though to brush up on a few key phrases.

The issue you may want to consider though is timing. Did you say you wanted to do the trip in early 2002? It is cold in Beijing in the winter, so if you only cared about miles, Singapore would be a better option.

If you are worried about things to do in Beijing, then I would consider going through a tour agent. I haven't used these guys but others have and the prices are really attractive

http://www.pacificdelighttours.com