An update after Part 2
http://www.noelwatson.com/blog/PermaLink,guid,19dadf64-9907-40cb-bf00-a27237df036d.aspx
At the start of the Football World Cup, Betfair were placing England as second favourites (I think at 7-1). I'm assuming this is because the majority of Betfair's market is from England, and were therefore placing lots of money on their home team, as I did not believe they were this good (I don't really follow football - but English football always seems to underperfom).
I didn't place any money, but if I had I would've probably laid England, as I as confident they were not going to win. I remember England being fifth favourites after the group games, but I'm not sure if their odds had lengthened as there were now fewer teams in the tournament.
For the England vs. Portugal game, I predicted that Portugal would win on penalties (note that I also thought Brazil would beat France, so don't follow my betting patterns!). I started to watch the game while also sitting in front of the P.C. to see how in-play betting worked.
Below are a few screenshots - note how the matched figure gets larger as time progresses (to prove I have the screenshots in the right order)
This shows that there may be opportunites after all
As an aside, I had a look at Betfair after the France vs. Portugal game had finished. Note how someone is still offering 1000-1 on Portugal. I guess they are hoping that someone hadn't seen the final score - France won.
This site is quite interesting
http://www.sportsarbitragereview.com/