The paper travel cards are just transport tickets for the tube/buses -- but being on paper and bought from a train station instead of a tube station they qualify you for the 2 for 1 entrance deals. Read the links yk provided.

It can get sort of complicated - but just remember - buy paper travel cards and pre-print the vouchers to get in 2 for 1.

Agreed with janisj. In addition to her example, you could also do Westminster Abbey in the morning and either St Paul's or the Tower in the afternoon (just be aware of the closing times), and do the Eye afterwards if you have time.

To address one of your earlier questions, I wouldn't worry about finding specific places to eat especially for lunch; you'll likely be busy seeing things. There are sandwich shops/cafes everywhere; EAT and Pret a Manger are two very common chains. I'd just grab something when you can. You might be able to plan a nicer dinner, but personally I'd rather see what I could of London in the evening than sit in a restaurant. Especially when you're going back to Paris!

Thanks so much for all your help everyone. I guess ill have to narrow it down and go from there. If I have any other questions. Ill be posting on this thread again.

Pret a Manger - owned in large part by McDonalds though i think. Caveat emptor!