Got a late start, but here's what I did yesterday:
Wellcome Collection: Henry Wellcome's collection of medical oddities, including a tanned bit of Jeremy Bentham's skin, with a bunch of writing on it.
Stern's Music: sadly, the world's best African music store no longer exists as a retail establishment.
Pret a Manger: they really need to bring their cucumber and tuna sandwiches to the States.
Muji: how absurd is it that three of the stores and restaurants that I first came to love abroad (in three different countries: Cosi in Paris, Pret a Manger in London, and Muji in Tokyo) now all have branches just a couple of blocks from my office in NYC?
Sir John Soane's Museum: still one of my favorite interiors in the world. It's funny that I like both minimalist modern interiors and cluttered folk art environments (that end up looking a lot like Soane's very non-folk art, but nonetheless very cluttered, interior).
Hunterian Museum: more medical oddities.
Sounds of the Universe: Soul Jazz's record shop in Soho.
Mentone Hotel: quick trip back to the hotel to drop stuff off.
Thomas Carlyle' House: Carlye, like Charles Babbage, hated noise, so he built a soundproof study on the top of his house. Turned out not to be as quiet as he wanted. It has no windows on its walls, but it's actually flooded with light from a skylight. I would love to have a small garden in the back like his. Here's the library he founded, when the librarian from the British Library turned down his request for a private room (apparently because of something Carlyle said about him).
Chelsea Physic Garden: contrary to what my tour book said, they were closed when I got here, so I couldn't see their recreations of mini-greenhouses built to transport ferns, that I had just read about.
Harrod's: bought Moses a present.
Michelin House: Conran's
Old Knightsbridge Village Pub Walk: tour of Knightsbridge and Kensington.