I like the Olympics - they are fun to watch and such great stories always come out of them. Since they are just around the corner, I keep finding myself thinking about jolly old London. It's such a great town for photography. The problem is that there is so much to do and shoot that you can never get it done. Heck, I live in Austin, TX and there are still things here that I haven't shot, and Austin is nowhere near as large as London. Anyways, I think when you get somewhere like that, you just hit the spots you can and fire shots as often as possible. If nothing else, you have a good time.
In this case I had been shooting sunset at the Tower Bridge, and was meandering back across it to get to the Tube and catch a ride back to my hotel. Being a fan of lights and water (and photography!), when I saw all this I just had to stop again, unpack my gear, and set up for a few more shots. Can't really blame me, can you?
BTW, the tall building in the center is The Shard, which is now completed and is the tallest building in the EU (per Wikipedia) and the round-ish shaped one that sits sort of center-left is City Hall.