I usually travel to London twice a month or more. Sometimes I happen to be nearby, otherwise I make a day of it. If I had to drive, or it meant "losing" hours of time to travelling I probably wouldn't bother. However, with mobile broadband I can spend the journey working, or just browsing the web, almost as easily as if I were sat at a desk. Once in Central London I usually travel around under my own steam, as I do if I punt locally.