I too have really curly hair, but I hardly ever straighten it (I don't really have the patience). I'm planning on pulling my hair back into a bun or a french knot with a few curls framing my face - it looks professional but not severe. I found a type of hair clip a little while ago that's been a lifesaver on days when I can't get my frizz to do anything:
http://www.drugstore.com/qxp142303_333181_sespider/vidal_sassoon/octopus_clip.htm I have several now and they work great (you can pick them up at walmart, cvs, etc.)
As to the OP, I agree with being conservative with your hair style, but don't be too drab. If you're normally an outgoing, funky person, find a way to express it somehow.