London is so vast I end up spending hours travelling on trains. They are by far the best way to travel around on and are always full of weird and wonderful characters.
I love the George and Dragon Public House. Cluttered deco of silly artifacts and memorabilia and slightly scuzzy around the edges. Great drinking characters, DJs and The White Cubicle gallery in the ladies toilets is difficult to beat.
A small place to eat with great vegetarian/vegan food just off Camden High Street. This place does an amazing buffet at a great price, as well as serving reasonably priced tea and juices.