Somerset House is currently hosting a free exhibit of photographs of London by architectural photographer Richard Bryant. The works on display are huge and lush and will make you fall in love with London. My favorites were a shot of the snaking river taken from the Citigroup building and a still life of wine glasses and bowls from inside the Dennis Severs House (which is really a wonderful place to visit at Christmastime).
You can buy his prints (on paper or canvas) here. There’s also a large, lovely book, which you can buy signed at the gallery. All of which has inspired me to take more photographs of London myself (and to remember to charge my camera battery before I leave the house).