Cdnuolt Blveiee Taht I Cluod Aulaclty Uesdnatnrd Waht I Was Rdanieg.

It works in Italian too, it's a relatively old "game". It just shows that people don't read one letter at a time, but they just "guess" and go faster.
It only works well with relatively simple sentences with relatively simple words, especially short words. It also depends on how the letters are swapped around, so the order matters a bit.
I tried to make it as difficult as I could, by the way. Here's my version: (it seems more difficult to me, but I can't really tell, since I'm the one who did it and therefore I am "biased" now).

Clondut biveele taht I culod alutalcy usdnnrated waht I was rinedag. The ponnahemel pweor of the haumn mnid. Andcirocg to raceresh at Cidrgambe Uitersnviy, it densot mteatr in waht oerdr the ltreets in a wrod are, the olny iaoptrnmt tnihg is taht the fsrit and lsat lteetr be in the rhgit pcale.

Wasn't there another reply here? I'd seen it... Now I don't remember what was in it though.
Anyway, I just think you don't just need the first and the last letter. You don't read one letter at a time, so you can just go faster and pick up "clues".
u...d
What word is that? You can't know. You need clues. Clues comes from context (whole sentences), length of the word, and the letters in it too.
uxxxxxxxxd
What word? Still too difficult.
undreanstd
Heh, seems easier. In context, it would be understandable. But notice that some "clusters" still give you some clues. Dr, st, ean, un... Let's swap them around and see if we can remove those clues:
usdnnrated
Seems more difficult. That's the one in my version, where I even tried to create some false clues, making it sound like something that might really exist (it ends in "rated").

So your brain needs clues to guess. I don't know what they are exactly or how many there are, but those who studied this thing should know. Interesting though.

WoW.... I read it successfully, looks like I'm really a genius . Here's the decoded message: Couldnt believe that I could actually understand what I was reading. The phenomenal power of human mind, according to a research at Cambridge University, it doesn’t matter in what order the letters in a word are, the only important thing is that the first and last letter be in the right place.

i coudn't beleive that i could actually understand what i was reading. the phenomenal power of a human mind, according to a reaserch at cambridge university,it doesn't matter in what order the letters in a word are, the only important thing is that the first and last letter be in a total mess and you can stil read it without a problem.
This is because the human mind does not read every letter by itself, but the word as a whole. Amazing huh? yeah and i always thought spelling was important!! if you can read this pass it on!!

Couldn't believe that I could actually understand what I was reading.The phaonmnneal power of the human mind.According to research at Cambridge University,it doesn't matter in what order the letter's in a word ar,the only important thing is that the first and last letter be in right place

I, too, read it correctly on the first attempt. This is maybe because we read a lot.

Couldn't believe that I could actually understand what I was reading the phenomenal power of the human mind. According to research at Cambridge university, it doesn't matter in what order the letters in a word are,the only one important thing is that the first and last letter be in the right place.