One neat idea is instead of starting the search from one node, start from both and see when the two search spaces meet. If the distance between two nodes is $k$ and the average branching factor in the network is $p$ then we explore $O(p^k/2^)$ nodes instead of $O(p^k^)$ nodes.
h2. Caveats

Unlike divide and conquer the trick in meet in the middle can't be applied recursively because the sub problems don't have the same structure as the original problem.
Bidirectional search can be often replaced by some search algorithm that uses some heuristics like A*.