Gio introduced me to the magic of FNV Hash a special kind of hash function well suited for hashing strings. Operations used for FVN hashing are bit-shift and xor. So they are pretty fast and guarantee to have few collision. No code this time, since the above web page has it already.
A comprehensive list of hash function is available here.
Update: Gio introduce me to the ultra-fast HSIEH string hash functions, which outperforms FNV hash. Again the code is in the page.