I won't pass too much judgment on Brits who can't spell because us Americans have problems doing so as well. When you read enough stuff, especially online, you come across some things that are down right annoying. So here are a few things that I come across a lot which are WRONG WRONG WRONG:

-- That championship game in the NFL is the Super Bowl. It says so on the ticket, program, etc. Not Superbowl. It ain't the game of steel, although there could be Steelers if you're lucky. The game got its name partly because of those other football bowl games like the Rose Bowl, Sugar Bowl, etc.
-- Those things that Barry Bonds hits a lot of are home runs (two words). When contracted, they become homers (one word). Sure it's hard to figure out with the abbreviations and all.
-- When you don't win, you lose a game. You might play loose in losing the game. You can't loose anything, you can loosen something, though.
-- There is no such word as definately. You definitely need to check your spelling if you use definately in your writing. Think of it this way, have you heard of a defination of a word?