I do, but not for the emo-kid effect. When I'm done, it doesn't look like it's been artificially straightened.
I'm growing an 80's sleezy-guy pony tail and my hair is at awkward length. I have to straighten it purely to keep it under some sort of control.
I'd really rather just pull it back and not worry about it. I hate awkward length. No idea what to do with it, and requires way too much product to look reasonable. My old pony tail was much less maintenance.