i found this awesome website on common errors in usage...if you're ever confused on affect and effect...or more obscure errors, he's must have thousands!
Someone should make a book with those definitions that had tear-out sheets or something so that us grammar police could issue "citations" and inform people of the proper use of oh...say THERE/THEY'RE/THEIR!!!!!!!!!!!!
Or...maybe I'm a huge bitch with some minor obsessive/compulsive tendencies.