Yesterday I went on the Eye, that impressive feature on the South Bank. It takes about 45 minutes the whole thing, you get on ski lift style and share a capsule with a bunch of strangers. I heard at least three different languages spoken in mine, not a word of which I understood. Je parle un peu francais but that's it.
I highly recommend the experience, all you need to know will be at www.londoneye.com so click on that and you're all set to ride 500 feet up in a 10 ton capsule! Tremendous views of the whole city stretching for miles, as if on a train out west in slow motion.