There's a thing called Cockney Rhyming Slang that I learned about first from Terry Pratchett's Dodger. I cannot do a description justice, so if you haven't heard about it before go to the link.
And then of course we have Leet-speak that is both a combination of substituting numbers and characters for letters as well as commonly mistyped words.
There's a bit of this out there already with people who actually say phrases like "BRB" and the like.
But this autocorrect thing.consider the most common and annoying correction to "duck".
I don't know if there are any other really common corrections, but it certainly got me thinking.