Should an applicant point out the typo and suggest if they were in the job last week, they would have caught it before the ad went live?
I've seen this done well, and I've seen it go horribly wrong. I've also heard people argue that it presents you as detail-oriented -- and others argue that it presents you as pompous.
I think it's fairly hard to pull off well, and potentially risky, but in the cases where I've seen it work, the applicant was sort of charming about it -- not pompous or know-it-all-ish, but had more of an attitude of "I'm sure this is a mistake no one noticed and I figured you'd want to know," maybe even with a little humor thrown in.
But again, you need to be careful.
I once had an applicant tell me a comma was misplaced when it wasn't. (Serial comma, how I love you.) If you're going to point out a mistake in this context, you really want to make sure that you're right.
What do you think? Would you be impressed or annoyed if an applicant did this?