I've carried a P229 concealed for several years
I tried carrying IWB, but came to the conclusion that it was just too uncomfortable. If you go the IWB route, you will have to get a quality holster, I liked my Milt Sparks holster, and pants that are a size or two larger than you would otherwise wear. I also have used a belly band as an IWB holster, but still found IWB to be uncomfortable. You might find otherwise.
I now carry the P229 in a Blackhawk CQC belt holster. I did find that an EXTREMELY stiff belt was far more comfortable than I thought it would be. I've been very happy with belts from AKJ Concealco (
www.concealco.com). Their belts consist of a metal or plastic band between 2 layers of leather. They don't stretch, don't twist, and don't sag. I've owned 2 in the last 10 years. There wasn't anything wrong with the first one, it just got, well, too small. Their belt page is at:
http://www.concealco.com/miva/merchant.mvc?Screen=CTGY&Store_Code=ACL&Category_Code=054BELT
For most business and casual wear in cool to cold weather (for me, October to April here in Northern VA) I can easily conceal the gun, cell phone, flashlight and 2 magazines under a polar fleece sweater/pullover. As long as you keep the garment loose and not form-fitting, you should have no problem. Nice and warm, too. In warmer weather, a vest or jacket conceals everything very well. In hot weather, casual attire consists of an untucked shirt, which also covers very effectively.
For really deep concealment, the belly band is a tolerable form of IWB carry for me, given that the pants are a size or 2 larger. Not as fast to deploy if the gun is needed, however. Re-holstering is kind of tricky as well. I've also carried a smaller P230 in a pocket holster. Put your hand in the pocket, grip the gun and you're ready to go.