Hi vtasurfmom, I’ve visited London many times (And we’re going back again this August). I have yet to see everything in London and it remains one of my favourite cities. I do agree with Dale that it’s not likely advantageous to buy the London Pass for first trips to London as there are so many museums and galleries that are free to enter (plus Changing of the Guard, Hyde Park, Outdoor markets etc that are free) . I did purchase the London Pass once when travel time was tight as some of their included attractions have ‘skip the line’ advantages. The Pass can be helpful if you are in London for a couple of days, are short on time and want to see at least three or four key sites per day to get your money’s worth. One unexpected advantage of having the London Pass is that it encouraged me to visit the smaller less known sites that were included in the Pass (Banqueting House, Fan museum, Cutty Sark come to mind...). I likely wouldn’t have seen these places if I didn’t have the free admission with the Pass. But I wouldn’t say that these sites, while interesting, are London’s top ten either (IMO). It’s best to research what appeals to you and your friend to see if the Pass offers what you would really like to see and what you have time to see with five days. London sites can be spread out a bit and five days will go fast. You could very easily fill your days visiting the free places and not have time to use your Pass!
Dale referred to the 2for1 admission coupon offers that are only applicable if you use the train to get to London (www.daysoutguide.co.uk). There are not a lot of offers, and there are limitations as to dates of use for some attractions such as London Eye, St Paul’s cathedral etc.but you might find that downloading these coupons works for you and your friend if taking a train into London from the airport or other towns.
Hope that you have a great trip. London is an amazing city!