If you're going to the Embankment then think about taking a boat trip up the Thames. There is a nice trip that takes you from Big Ben towards Tower Bridge ... you'll pass The Tate and a few very nice landmarks.
Of course, if you go up The London Eye, you will get to see so much .. just make sure to have a Circular Polariser to try to defuse the reflections out of the windows. While up there, try to get some shots of passengers in cabins infront and behind you .. you may be happily surprised if a sexy person posed for you (a model did that for me in my last trip up there .. and wow was she hot and new how to pose).
Another area to cover is Canaray Wharf (sp.). You can spend a whole day out there, and if you are getting the travelcard you can get to there relatively cheap. I did a silly mistake by taking a taxi to there (cost me a good £40) .. but was well worth every pence spent. Keep in mind, you may need prior permission to photography in that part of the city. I was asked by security not to shoot, since I seem to have had "professional" gear with me. Still, I managed to shoot a lot and it was a wonderful experience.
If you go down the other end of The Thames, you can go to Kew Gardens and the Botanic Gardens. Check that out, it is fantastic, espeically if you want to try and do the "Tree Top" walk. You may be lucky with what you see.
Sometimes Regent St. is closed for some off event. They've done this a number of times in the past week. On one occassion it was for the London to Brighton car race; on another occassion it was a Spanish Festival with all sorts of Spanish dancers (very hot and exotic); on another occassion it was a food festival. The times were too many to list here.
You can then enjoy Covent Gardens. Lovely lively place to go to.
No visit to London is complete without a walk in Bond St. (both Old and New) ... there you can shoot some of the most exotic cars in the world. Just parked for your eyes to enjoy. RR Phantom, Mercedes SLRs, Lambourghinis, and the list goes on and on and on.
If that's not enough, you can cover all that walking which would take you about 8 hours. Very much worth every blister you may develop.
London is The Capital of Earth .. and it should rightfully be named so. You just can't get enough of it, but a bit on the expensive side.
If only someone would give me a limit-less credit card, I'd be a happy Londoner
