London is a great city to visit.  There are so many things to do that a weekend or even a week will not even scratch the surface.  Luckily, there are as many things to do inside (Madame Tussauds, British Museum, National Portrait Gallery, palaces, theatres, cinemas - not to mention the shopping!) as there are outside, which is just as well as the weather can be quite variable!

However, when the sun does shine you can take river trip on the Thames, stroll around one of the Royal Parks, experience the London Eye, etc etc.  

Bars and restaurants are great.  No longer is UK food bland, stodgy and boring...and the bars are generally lively and fun.  There is no smoking in the UK any more - something which has given the city's people even more hardiness as they spend time sitting outside, wrapped in coats and scarves, smoking!  Anyway, that is great for the no-smoking crowd (including me!).

Gay London is also absolutely fabulous.  All I can say is come and experience it....