If part of your job application strategy is going to be to point out a grammatical error on the employer's Web site, please make sure that it's actually an error.
I received a cover letter last week that opened this way: "Despite my eagerness to learn as much as I could about the position, the first thing that I noticed on your Web site was a grammatical error."
She then quoted the "error."
Except that it wasn't an error. It was perfectly correct. She had a misunderstanding of comma usage.
Now, I am obsessed with grammar and usage, and I am all for pointing out possible grammatical errors, but if you're going to do it in a cover letter, you really, really want to be sure that you're correct.
Otherwise you look both pompous and silly (and in her case, not very bright), and it's not a good thing when the hiring manager feels embarrassed for you.