I have the worst looking hair of anyone after it has been under a helmet. I have several solutions:
Buff. I have worn one around my neck and then pulled it up like a sweat band or bandana after taking my helmet off. Now I wear it over my hair and pulled down on my forehead a little because I was having a problem with sweat running in my eyes. There are really cute ones, too.
On a tour, I carried a hat with a crushable brim that I put on immediately after taking my helmet off.
Now that I know about cycling caps, I like that idea. If I didn't have such an investment in buffs, I would get one!
I sympathize completely.
Grits
2010 Trek 5.2 Madone WSD, SI Diva Gel Flow
2002 Terry Classic, Terry Liberator