The food is incredibly bland and tasteless, be it Italian, British, Chinese, American or English. And very expensive. As in $15-20 CDN for an order of wings. Stick to Indian/Middle Eastern food... if you have taste buds and enjoy food.
Kensington (Diana's palace) is a great park and a great place for a walk/run. You should definitely shop for nice threads - they are great quality and surprisingly well priced. The added bonus of being on the main fancy shopping street (damn...... the name slipped my mind - it's around Piccadilly I believe) is that you will see some absolutely stunning, model-quality women walking around
Of course, check out the usual tourist sites. EDIT: Forgot to add, if you are culturally minded, definitely go to the theater - better than anything you'll see on this continent, perhaps outside of NY. You can see Captain Picard starring in something.