Advanced Contacts Search

The idea is to have an "All Fields Search", which would look for matching string/s in any field.
Having this function incorporated into quick search would be good, or at least being able to index fields for the quick search function (so if your company is more organisation-centric for example, being able to search by division and section would be better than individual names (people move, companies generally don't)).
Thoughts, improvements, suggestions, doubts?