Belhassen on "resume question"

I'm thinking about dropping off my resume at a few particular places of employment. I have no idea if they're hiring, but it can't hurt to try.

I've never passed along my resume without an interview or invitation. So that it looks professional, I will include a cover letter, but do I put them in a plastic sleeve? An 8.5 x 11 envelope that matches the stationery? Folded in a matching envelope?

Thanks!