I got back from London at about 1:00 am Thursday morning and man did I have a good time!  It was a blast.  I'll give you a day-by-day of what I did (which was a lot!!!)
Day One:
Got up at about 6:30 and caught the bus to the metro station, took the subway to the train station and then the other bus to the airport (a lot of work, I know).  The flight went very smoothly and we landed at about 11:00.  I was a little bit amazed that it was an actual normal jet that we flew on after paying only 30 euros round trip for the flight!  From there I took another bus ride a little over an hour to get into the city.  Finally there!  It was really nice being in a city where people spoke English haha. Made things much more convenient.  After I got off the bus I decided to walk over to Camden Town and check out the Sunday market.  I walked through Regents park to get there which was really really nice.  Everything in the royal parks is very well groomed and it all looked really nice.  Made it to the market and man was it huge.  There are just markets everywhere there!  And lots of cheap food too.  I got a great hot dog for lunch and it was only 1.50 (made me feel at home!)  From there I wandered through all the other markets and proceeded to get lost without a map.  Got directions and ended up walking along the Regents Canal which borders the park and goes right through the London Zoo.  So I got to see some pretty cool animals as well!  At that point I figured I was pretty close to Abbey road so I may as well go check that out.  IT was really fun!  Lots of people there taking pictures.  I got a few as well.  After that I decided I better head toward the hostel since it was getting late and I had a very very long walk to get there.  Finally arrived and got my bed made then went out to get some dinner.  The hostel was an interesting place.  Pretty nice actually, but my room had 12 beds in it (and it wasn't a very big room...).  But hey, for 8.99 a night it was a pretty good deal.
Day Two:
The next day I got up at about 7:30 and ate breakfast at the hostel.  They provided all you can eat toast and tea.  I took advantage of it.  I then headed to the metro station and bought a day pass for the tube and the busses.  Took my first ride on the underground!  It's a really good system, with stops all over the place.  I first headed to the British Museum, which was one of my favorite places in the city.  They have a lot of really cool stuff!  I even saw Cleopatra's mummy!  There was a really good Egyptian exhibit going on right now.  Pretty cool stuff.  From there I went to Soho, then took the tube to Westminster.  I saw Big Ben and the houses of Parliament - pretty darn impressive.  I also saw the London Eye and Westminster Abbey.  From there I went and checked out an old church then headed to Picadilly Circus.  I wasn't really impressed with that so I headed back to Camden for some lunch.  Got some great fish and chips.
After that I went over to Hyde Park and walked around for a bit.  I ended up walking further than I had expected and found myself at the Albert Memorial, right across the street from Royal Albert Hall.  Both of these are pretty cool to see!  After that I hopped on a double decker bus and headed to Notting Hill.  Very nice there.  Also checked out Kensington a bit.  At that point I had no clue how to get back to my hostel by Hyde park, but ended up finding a very convenient Underground station close by.  One of the stops was about 50 yards away from the hostel so it worked out really well.  Went for some more fish and chips, then checked in for the night.
Day Three:
I had a pretty full set of plans for this day so I wanted to get up at 7 to get breakfast and head out as early as possible.  I ended up waking up at 7:30 and frantically got dressed only to discover that somehow I had gotten up at 6:30 and breakfast wasn't ready yet (time difference got confusing...)  Ate tons of toast (8 pieces to be exact) and drank lots of tea then headed out.  I ended up getting on about 4 different underground lines (lots of delays that day) but finally made it to the Tower Hill stop.  I saw the Tower of London (really cool!) and then walked across the Tower Bridge.  This was really impressive.  It's huge!  I spent some time on the south side of the Thames, then headed back across the bridge and went to St. Paul's Cathedral.  Wow!  Huge!  It was really cool.  I went inside, but they were charging 11 pounds to tour it.  Not worth it to me.  From there I headed to go see the Tate Modern art gallery.  I ended up stopping at another really nice cathedral with an enormous tower.  I wasn't sure if it would be open, but I tried the door and sure enough, it was open.  I was the only one in there for maybe 20 minutes or so.  It was really cool.  After that I went and explored the Tate Modern.  Better than I was expecting!  Lots of really cool art there including works from PIcasso, Andy Warhol, Monet, Matisse, and many more.  It was really cool.  After that I checked out the Globe (right next door) then headed back to Camden for lunch.  I was a big fan of the 1.50 pound hot dogs!  From there I had to take a trip back to the British Museum as I realized that I'd somehow missed the Rosetta Stone last time!  It was really cool to see it in real life!  A lot bigger than I had imagined.  Pretty amazing when you think about what you're looking at.  I also saw a lot of really cool egyptian statues including one of Ramses II.  Pretty old stuff!  From there I headed to Regents Park to explore it a bit more.  I spent a lot of time sitting by a pond in Queen Mary's Garden. Very peaceful.  Also my knee was hurting from all of the walking so it was nice to sit for a while!  I had seen all the major sights at that point so I decided to take it a bit slower and enjoy my time there.  I met an old man in the park who gave me a map and suggested I go to Primrose Hill just north of the park as you get a good view of the city.  Despite how tired I was at that point, I decided I'm only in London once so I better just go do it.  Boy am I glad I did!  It was one of my favorite places in the city.  You walk up this big grassy hill at the edge of the park and get an absolutely beautiful view of the city.  I was there at dusk too so I got to see an awesome sunset and after I got to see the city all lit up at night.  Well worth the trip and as it was my last night, it was a good time to reflect on all that I had seen in the last few days.
Day Four
On my last day I got up and ate my usual half loaf of toast, packed up all my belongings, turned in my sheets and checked out of the hostel.  Interestingly, I was a bit sad to leave haha.  I didn't want to buy another travelcard for the day since I was leaving at 3:30, so I walked to Kensington Gardens and headed toward Buckingham Palace to see the changing of the guard.  Two hours and 2 more parks later (Hyde Park and Green Park), I finally arrived at the Queens "house."  What a pad!  The whole royal thing seemed a bit strange to me though.  There were a bunch of guys dressed up on horses blowing trumpets with flags on them and marching around and yelling - just to change work shifts?  Definitely a really cool ceremony to watch though!  I enjoyed all 30 minutes of it.  After that I headed to Oxford Circus and changed out my remaining pounds for euros.  Then I headed back toward Regents park to catch the bus back to the airport.  I got there about 2 hours early, so I got some lunch and enjoyed it at the park next to a very nice little river.  It was an awesome place to spend my last couple of hours in London.