Dose spilling rilly mater?

Poor grammar and spelling mistakes are two things that I am apt to notice right off the bat. Even my fiancé, who isn't nearly as nit-picky or sensitive to language variation as I am, complains rather frequently about how often he encounters spelling errors in his day-to-day business and personal correspondence. Why is this? Have we gotten so lazy about communication and taken our casual  channels of communication, like email, twitter, Facebook, and IM, to such an extreme that we don't even care if our language is correct as long as it is communicative.
     Most of us have seen this well-circulated example of how our brains can comprehend a passage even if every word is spelled incorrectly: "Aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is taht the frist and lsat ltteers be at the rghit pclae. The rset can be a toatl mses and you can sitll raed it wouthit porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe."
     It is an interesting cognitive ability, yet when we refer to it in terms of the importance of spelling, you must take into account the many years of schooling we have all had to get to where we are now. If we didn't already have a solid knowledge of spelling, would we still be able to comprehend the passage above? If we all forsake spelling rules and begin writing carelessly, will our English still be the same language in a few generations?
      I read an article today on FinancialTimes.com called If You Want a Job, Learn Your It's and Its. It's an extremely interesting article that I'd suggest you read. The author, Michael Skapinker, quotes several employers who claim that they would not hire someone who made spelling errors such as confusing "it's" with "its" or "they're" for "there" or "their." These employers are skeptical about such a person's ability to pay attention to details on other tasks, as well as the cause of their inability to straighten these problems out in the twenty plus years prior to seeking work at the companies in question.
     As a translator, I am a writer and a lover of language, so spelling errors often feel like garlic to my inner writer vampire. Maybe we can raise awareness and help some people correct their "your" and "you're" usage! Okay, probably not, but at least we can laugh! Besides the few examples I mentioned here, what are some of the other most frustratingly common spelling mistakes (in English or Spanish) that you see around? Comment below and let's get a conversation and a good laugh going!