Crippled Monster :S

[MrBigzy]

It's edit->delete all by type or delete by type, and then history.

I don't think you can delete history on a binded mesh though, you'll have to unbind it, delete history, and then rebind it. You can save your weights when unbinding by choosing the options box and picking bake weights, but it still might not be the same when you rebind, so you might have to repaint weights and what not again.