kbaby: here are the things I've tried and had some success with. Consider it a pick and mix of things for you to experiment with
cranial osteopathy - not cheap. see if you can get a cranial osteopath recommended in your area - you should look for one who has particular experience with babies. Mine cost £32 for first visit and £25 for follow up visits. Had two sessions so far and seeing some improvement in reducing windiness.
infacol - can buy in chemist/large supermarket and you give a dropper full before a feed. Helps the air bubbles to be burped up more easily.
dummy - gives them something to suck on and be soothed by. I'm trying to limit use just to calm him down then remove, rather than let him sleep with it partly because I don't want bad sleep associations, partly because I'm not sure if it's creating more wind.
white noise/womb sounds - ds2 has a bear that emits womb sounds when he cries or for 5 mins after you press it. Not sure if it's doing anything, but hey, it's worth a try.
blankie/cuski doll - something with your smell to put in the cot as extra comfort.
burping - I have 4 different burp positions I work through for about 10 mins after a feed. The first sitting up, chin in my hand and gently rubbing his back in a circular motion. The second over my shoulder again rubbing his back. The third lying over my knees (similar principle to tiger in the tree hold, except he's too long for my arm!) again rubbing in circular motion. Fourth on his back and I bicycle his legs.
crying - recently his cues for tired/in pain/hunger have become a lot more obvious in the last few days. As a result I'm more prepared to let him have a short cry (5-10mins max) on his own to settle IF (and only if) I'm 100% sure he's just overtired and fighting sleep not in pain or hungry.