Interesting topic, I've enjoyed reading the responses!
My first 4 years in the UK, I had a "carpe diem" attitude and spent every weekend trying to "suck the marrow out of life" (quote from Dead Poets Society). � This included traipsing all over London as well as taking weekend trips away with a variety of travel companies (some of them cheap and cheerful) which took me to places such as the Isle of Wight, Devon and Cornwall, Belgium, France and Germany (yes, all in just a weekend!). � TNT Magazine is a great source for these tour operators, as they cater to the Antipodean (and South African) crowd, many of whom are only planning to be in the UK 1-2 years.
These first 4 years coincided with a period of instability in my life before I had ILR (work permit route). � Once I obtained ILR, my life changed dramatically and the carpe diem effect wore off (granted, I am also getting old!)
In my last 4+ years in the UK, I have tended to stay close to home and do more of the types of things I used to do in the USA (errands, window shopping, just kicking around at home). � I live on the zone 3/4 border in West London, and tend to hang out within a 1 mile radius of my house at weekends, which includes Chiswick, Ealing, Kew, Richmond and even Hounslow (for shopping). � My current job takes me out to Surrey during the work week on the overground train, so I rarely have to use the tube, and on the rare occasions that DH and I do venture into central London, I am reminded as to why I now actively avoid it!