You could use your long hair to weed out employers who you wouldn't be happy with -- echoing the earlier statement that one who doesn't like long hair will probably have other issues too. If you "have" to cut your hair to get a position with a firm, there's a chance that firm will *never* accept long hair when you want to grow it back.

Unfortunately there are a lot more of "them" (dislikers of long hair) than there are of us. Still... well, I'd think a ponytail should work out.

*fingers crossed for you*