You don't want a compress/limiter, and you don't want a sock - for all the reasons stated. What you want is a PAD - or, to be specific, an iPhone app that allows you to PAD, or attenuate (or control), the incoming signal. A compressor/limiter will just smack the sound like a hammer, and it's not going to help you. It's already a condenser mike, so it's going to be able to catch the subtle stuff ok (though if you're in the crowd, people talking nearby will probably be louder). If you can find an app that gives you a pad on the signal, you can "tune" it for the loud parts, and the condenser //should// take care of the quieter stuff. You just want to make sure that you don't go "into the red" -12db or 0 db, depending on which kind of standard the pad is using, and it should be fine. Good luck! And be sure and come back and tell everyone what you did!
Cheers,
-Kelly
PS - Blue mics really rock, especially for the proce. They're a great value. Full disclosure: I don't work for Blue or have any connection with them of any kind.