The best tours are the ones done by guides who work for tips. That was the theory of my New London Tours guide, and it certainly was true. Offered daily at 10am, the tour was one of the best tours I've ever been on. My particular 3-hour tour covered all of the basics in old London including: Saint Paul's Cathedral, London Bridge, Shakespeare's Globe theater, Covent Gardens, Church of the Knights Templar, Trafalgar Square, and Westminster Abbey. I have seen all these sights before, but the tour guide provided some fascinating history and interesting facts that made the tour both worthwhile and memorable:

Tap water in London, which comes from the Thames river, has been through 8 people before you

The London Bridge is often confused with the picturesque Tower Bridge. The most expensive case of this confusion was the auction sale of the London Bridge to American entrepreneuer Robert McCulloch for nearly $2.5 million dollars in 1960. The tower was reconstructed in Arizona and is now the number 2 tourist attraction, after the Grand Canyon.

With some Harry Potter and Da Vinci Code trivia thrown in, the tour was definitely worth the time and tip!