Theres a feat for doing 2d12 or something while pinning someone, Earthbound or such from Races of Stone I believe. It does make things interesting. that and while pinning casters are FUDGED LIKE CHOCOLATE, so its all ok.
Another point to be made, Spikers, from the Planar Handbook make half decent Fighter grapplers with there natural armour spikes, which you can put into a mithril breastplate and run around as a barbarian in. Theres a few builds for grappling, but the trick is that for larger creatures, you're boned. Psychic Warrior takes care of part of this by Expansion, a nice power, but getting the power points you need can be a hassle. Dont fear the grappler being a weak build, it IS but theres many ways to make it work.