Almost every forum I go to has grammar nazis. Yes, I do understand the difference between their, they're, and there. However, sometimes I type too fast and use the wrong one. However, most of the time people can connect the dots and the point gets across.

I hvae a felinig you can raed tihs snice the huamn brian lokos at the frist and lsat lteters of wrods isntaed of the wohle thnig.