[rmccue]

To expand on what has already been noted: a good place for fast hashing is when you're using hashing millions of objects. For example, if I wanted to parse thousands of feeds and store items using a unique hash as their key, I'd want a fast hash that's collision resistant (for the uniqueness part) and one that's fast (for the millions of objects). With password hashing (KDFs, as tptacek noted), the collision resistance is useful, but we want to keep it fairly slow to avoid being able to brute force attacks.