It seems you have the big hitters for London itself. There is tons to do there. I am sure it is on your list, but don't miss the British Museum. I am not a huge museum person, but this one is a cut above and is worth it just to see the Rosetta Stone. It has other cool stuff to see that can get you through the inevitable London rainy afternoon.

Some of the day/side trips I have done and really enjoyed:

- Canterbury - the cathedral is very nice and has some odd, but cool, angles and curves. The spot marking where Thomas Becket was murdered also brings history to life. The town of Canterbury is very charming. I was going to combine Canterbury with Dover, but I just stayed in Canterbury. You can do both, but I tend to really slow down in places I like just walking around. I'll hit Dover another time.

- Hampton Court - Lots of coolness factors going on here if you are an English history buff. Plenty of buildings survive from Henry VIII. I spent a whole day wandering around visiting all of the different wings. You can do the Henry VIII buildings in a couple of hours.

Salisbury - the cathedral is awesome and you can also see an original copy of the Magna Carta. Be sure to do the tower tour. Obviously, you see the tower, but you see sooooo much more as you wind through the guts and walls of the cathedral which includes the space between the roof you see from the outside and the ceiling you seen inside the church. Also if you go, don't miss the chapter house. There are carvings going around the inside that depict Old Testament scenes. I visited with a friend and the priest/layman assigned to talk to visitors in the chapter house was surprised we were able to name nearly all of the scenes. OT Sunday School lessons for the win! I have heard the old town is worth a stroll, but I did not visit it.

My best advice for London (or anywhere really) is assume you will be back. Don't try to pack so much in that you spend all your time in cars or on trains.