A friend just wrote to me, asking about agile. He's been seeing software job posting with the vague request/promise of "agile" in them, wondering what the big deal is. Initial reaction: if no specific methodology or agile principle is cited, then at worst they are glomming on to pop culture, at best they want to make sure you can (a) handle changing requirements, (b) deliver prototypes and/or working code frequently, (c) take an iterative approach to documentation, coding, and testing.
"Being agile" means both that you aren't going to freak out at the lack of a locked-down, step-by-step waterfall process, and that you aren't going to go cowboy and give the client a product at the last minute, with no conversations or demonstrations between the initial requirements "gathering" and delivery.