I'd second the reccomendation of Yauatcha, in London - the tea-room over the restaurant (vast lists of teas, and marvellous, indescribable sweetstuffs) is one of my favourite cafes in town. Review here: http://www.timesonline.co.uk/tol/com...icle420531.ece.

China Tang, at the Dorchester Hotel, is rather lovely, too. (http://www.thedorchester.com/restaur...hina_tang.html)