A configuration is a finite set of points with no three collinear. Two configurations have the same order type if there exists a bijection between these two configurations that preserves the orientation of every ordered triple. A configuration A contains a copy of a configuration B some subset of A has the same order type of B and we denote by B \subset A. For a configuration B and an integer m, the extremal number
ex(m,B)= max {|A| : B is not a subset of A, A \subset [m]^2}
is the maximum size of a subset of the grid $[m]^2$ without a copy of $B$. We discuss some bounds on this function for general B.