Albeit awkward and semi-gay, the yoga for surfers DVD shows you some really good stretches for your pre-surf, post surf and during surf exercises. Its really basic stuff, not even real "Yoga", but its enough to get you loosened up before a surf or on your days between swells.
With that being said, simple calisthenics will do the trick. Just simple team sports/track and field stretching will suffice... Hardest part is finding motivation to do it
I like the "figure 4" stretch. Lay on your back like a sit up, feet flat on the floor. My left hip gets sore so i cross my left leg to my right. Basically putting my ankle to my femur just above my knee. I put my left arm in between my legs, using both arms i try to pull my right leg to my chest. Take your elbow and use it to try to push your opposite knee away. This is hard to explain, google may have a picture. As Dawnpatrol was saying the doggy style hip flexor stretches are your best bet.
Dead end. Your surfin starts sufferin. Family, surf, all else is dust in the wind. Lay of the hard stuff and stick to the herb and liquid poison. Dude, go get some Xanax and a bunch of weed. Go to a buddies, dry out for a week. Get away from your connects. Lose their numbers forever. Good luck, HOLD FAST.
I swear by Yoga. The place I work brings a gal in once a week. An hour once a week of dedicated stretching and you will see amazing results. If you have back or neck pain, it will help. I run and lift some too. Get a chiropractic adjustment every 6 weeks. I surf just about everyday too. Stretch before every session. Probably get in between 6-12 solid hours every week.