I have my test Oct 5-7th...so, not yet. I'm a certified group fitness instructor through AFAA (www.afaa.com) and my PT cert will be through AFAA too. From my understanding, ACE & AFAA are the two major certifying bodies in the US, and are accepted virtually everywhere. Check 'em out: www.afaa.com, www.acefitness.org.
First came LOVE ♥ 01.19.00, then came MARRIAGE ♥ 05.25.03
and then a BABY CARRIAGE ♥ 03.22.05
ACSM is another good one. If you want to make your living off of it I would highly recommend getting a lot of other certifications in group fitness. It will make you more appealing to a gym and you can supplement your income. If they gym you want to work at has a pool then that is another avenue to explore.