I read an interesting book that in part dealt with product placement in movies and how 9 times out of 10 its a huge waste of money for companies to do. Unless the product is an integral part of the movie's plot (i.e. Reece's in ET - also fun story that the Mars company was approached first to put M+M's in and they refused, sales of Reece's Pieces spiked after the movie, but anyways) the average consumer will not be influenced at all. So if your favorite hero is drinking a coke, it won't actually make you more likely to buy coke, unless he spills the coke on himself and is like, oh man, coke on me, now I need dry cleaning... (even that's a stretch)... but yeah watch any movie today, the product placement is ridiculous; yet trying to remember what is actually in the movies is tough... I remember seeing Hancock a year or so ago and there were tons and tons of product placements, I remember a car, but can't remember the make, he had a drink he really liked, can't remember it, etc....
I disagree somewhat. Like if Coke spends millions to have Shai Lebouf drink a Coke in Transformers, it's not going to do too much, but it's the more subtle things in movies geared towards more impressionable people (like kids and tweens). If the cool kid is wearing Nikes in a movie, the impressionable kids see that and associate Nike with cool kids, an impression that will be with you a while, even if he doesn't fully realize ir.
Anyway, how about the movie The Wizard for Nintendo products placement, Super Mario 3 and the Power Glove both made their premier in that movie, which was basically a 90 minute Nintendo commercial.
Just watch this Angry Video Game Nerd video about it, hilarious and good stuff:
http://screwattack.com/AVGN/2008/SMB3