It mostly depends on what I'm doing and if anybody has already answered the shouts. (I always, always get beaten to it.)

If a greeny actually talked to me though, through tells or whatever, after panicing a bit ('holy crap they are talking to me waaahhhh /shy /shy /shy'), I'd probably help them out if I had the time. I like running through the low level dungeons (a oddity, I know.) and my crafting is such that I could probably help get them geared up on the left if they needed.
Unless they were mooching for gil. Then they can get bent.