This website offers discounts on anything, from walking London tours to theater tickets. In order to qualify, all you need do is visit the website, DiscountLondon.com, to book your attraction through them. Examples of their discounts include 10 percent off the Open Top Bus Tour.
Go to LondonPass.com and click on "buy now" to purchase your pass. As of 2010, prices range from £70 for one day to £420 for six days. You then have free entry to 56 London tourist attractions such as St Paul's Cathedral, which costs £12.50, or Hampton Court Palace at £14. The London Pass cuts out queuing time too.
Visit DiscountBritain.net to print out your Smartsave 20 percent off voucher, valid for up to six people. Then simply show it at the ticket counter at any of a multitude of tourist attractions such as The London Dungeons, St Paul's Cathedral or The Shakespeare's Globe Theatre and Exhibition Tour to get your discount.