August weekend in London ideas

[magicstar1]

My friend has got us tickets for Bros in the O2 so we're flying into London early Saturday morning, concert that night, and flying out late Sunday evening.
We'll be staying in the Novotel in Canary Wharf...would anyone have suggestions of what to do for the two days? We wouldn't be into expensive shops, but maybe markets or something?
Thanks

Buckingham palace, river trip, London eye, V&A museum, afternoon tea at a nice hotel, wander through Hyde Park. All of the above apart from museum and park need advance booking.

Time on the south bank or Covent Garden watching the street entertainers

In addition to above suggestions, the following are all free or cheap and good fun (at least I think so!)

Camden market (north London) or one of the smaller trendy markets in east / SE London eg Broadway market, Columbia Rd flower market or Maltby St Market

Greenwich or Richmond - both very nice, on the river (opposite ends of the the river!) and have big parks and good pubs and places to eat

Hampstead - "village" in north London with a big heath and cosy pubs

Take the Thames Clipper boat along the river (it's a commuter boat so not too ££)

Go for a meal in Chinatown