The very concept of "MAP" dictates that you won't find an online dealer selling for below MAP, assuming you're buying on a shopping cart site (B&H, Adorama, etc). Just like guitars, though, if you get them on the phone, they're free to sell below MAP.
Unlike guitars, though, the profit margin on photography equipment can be ridiculously slim. A good buddy of mine used to work in a local shop, and he would always try to cut me a good deal. He would freely show me his cost, too, and it was high when compared to what he was selling gear for. If they weren't selling at MAP, it could actually cost them money to make the deal (depending on the product), and no one is going to stay in business very long if they do that...