What’s the best hashing algorithm to use on a stl string when using hash_map?

I worked with Paul Larson of Microsoft Research on some hashtable implementations. He investigated a number of string hashing functions on a variety of datasets and found that a simple multiply by 101 and add loop worked surprisingly well.

unsigned int
hash(
    const char* s,
    unsigned int seed = 0)
{
    unsigned int hash = seed;
    while (*s)
    {
        hash = hash * 101  +  *s++;
    }
    return hash;
}