What are some great things to do in London (on a budget)?

Go to the British museum. It is free and fascinating. I have been many times and each time see something I didn't notice before. This also leaves you very close to all the restaurant spots for the evening. You will be near the West End and Covent Garden etc all within walking distance.

The Hard Rock Cafe Museum has a lot of cool exhibits. Not free but you and your pal might like it. The British Museum is a good idea. More than enough to see and not at all stuffy.

Most of the London museums are free.....catch a tube train to Lambeth north and visit the War museum. You can watch the street entertainers in Covent Garden...(but they do want a donation off the people watching) Shopping....but clothes are generally not cheap in London. Boat trips down the Thames...or a bike taxi to Trafalger Square... Millenium Wheel.... Enjoy :)

British museum is great, Boat trips down the Thames, nice cafes in Piccadilly Circus, nice shops on oxford st.

get ur mps players synced up to play the same music, press play with all your favorite songs... dance around the city singiing... be careful with the men, some are actually out to hurt people... i would find some nice clean rooftops to hang out on, and see the beautiful city at night... get some fish and chips, but not too much, they'll do a number on your stomach... get some nice food in a market, make a good dinner, healthy, and eat it on a nice balcony, or at a friends nice flat... catch a movie, or rent a fav you both have... but really dancing and good eating is great fun, maybe u can get to a free open mic and sing for a group of total strangers, or get to a cheesy atempt at kereoke in a fun young pub... good luck and remember the mission is to have fun... lol sing and dance is a good way...