Pff… Don’t worry about it. Typos happen. I’m not an Internet Grammar Nazi (TM). They happen to all of us. Although it’s instantly embarrassing when you realize it. And it sucks. And it makes me never want to write anything ever again, anywhere.
And for the record, even though people I love and adore do it (I still love you guys!), Internet Grammar Nazis are least favorite thing about social networking.