I've never really thought about some of the regulations in the game of football from the perspective of making the game portable, so I found Ed Felten's take on How Not to Fix Soccer interesting.
I've long been aware that a lot of US schools shun American football in favour of regular football (I'm not saying soccer you idiots) because all you need is a ball to play, so it's a lot cheaper, but I've never broken down the reasons behind it.
There is one thing, one reason, he forgot though: flow. There's a reason football reaches such great crescendos of excitement that most sports don't: it's non-stop. Everything is designed to allow the games to continue for 45 minutes largely uninterrupted. Unlike American football, or hockey, or baseball, where they even stop for ad breaks. To quote Wikipedia:
A standard football game consists of four 15-minute quarters (12-minute quarters in high-school football and often shorter at lower levels), with a 12 minute half-time intermission after the second quarter. The clock stops after certain plays; therefore, a game can last considerably longer (often more than three hours in real time), and if a game is broadcast on television, TV timeouts are taken at certain intervals of the game to broadcast commercials outside of game action.
So a game that should take less than an hour-and-a-quarter regularly goes three times that. Maybe they need to look at the rules of their own games and simplify them to make them run faster.