London Pass?

There are plenty of quite recent threads on this - lots of opinions out there. Personally I wouldn't use it as I don't want to rush around ticking off sites to justify the cost of the pass. I would advise thinking first about how much time you have an what you want to see, and then looking at whether the cost is justified. I doubt it will be unless you really are on a whistle-stop tour.

The issue with the London Pass is that many of the great London attractions (the big museums - British Museum, National Gallery, V&A etc) are free entry. So you might find yourself chasing around to get value out of the London Pass and missing the amazing stuff that it doesn’t cover.

Yes, the London Pass can be great. I saved over 140 pounds on my last trip to London on admissions and did not (contrary to the posts above) run around in a frenzy trying to see everything.

The first thing to do to see if the London Pass is right for you is come up with a rough itinerary. I generally limit myself to two major sites in one day. Then, price out the admissions of the sites you are interested in. Compare this with the price of the pass and see if it provides value for you. Sometimes it does and sometimes it doesn’t.

A few other tips. The longer passes seem to provide greater value than the shorter passes. The London Pass often allows you to skip ticket lines, but never security. A few locations do require that you make reservations, but the directions are clear on the London Pass website.

The London Pass works just fine and can be a money saving convenience. However, each person should price out admissions and compare before buying

Carol, Golden Girl, and Simon have all given you good advice. Carol has nailed it, as far as outlining how to get the best value and figure out if the pass will work for you.

An important fact to consider is that there are many free museums in London, as Golden Girl said.
She has listed some of the most important ones, but there are perhaps two dozen others that are free. Some of the world's greatest treasures are in the British Museum....free to see....no pass needed. Likewise, the Victoria & Albert Museum (V&A) is free and contains treasures of all kinds....from medieval tapestries to Tudor jewelry, Henry VIII's writing box, silver collections, paintings, and more.

You could spend three days at the British Museum and still not see it all.

Do research and see what's on your itinerary you make for London. Then, as Carol said, you can see if the pass will pay off for you. You may find yourself spending more time at the museums and less time at tourist attractions that you pay to get into, such as the big wheel.

There are also guided walks around London that are excellent. You might wish to do a couple of those instead of the usual tourist sights. See www.walks.com for more info including a great Harry Potter Walk they do.
These are not included with "the pass" but are really inexpensive and fun. One of their walks includes a walk past the Tower of London and a telling of its history. Not everyone who goes to London wants to take the time to go in there. If you're really an English history buff, yes. But, if you'd be going just because it's on every tourist must-see list, then perhaps skip it because of the expense and the time it takes to wander through.

Customize your itinerary to what you would really like to see and do, not what "everybody says you should see" tourist things.

Just as an FYI, there are several walks included in London Pass, just a different company.