We promised you we would add to askeet the feature that the symfony community would ask the most. We secretly dreamt of some easy-to-add feature, but the community really insisted on having a search engine. So we developed an easy-to-add search engine.
It's all in PHP, database independant, with ordering of the results according to the relevancy, weighting of the indexed words, etc. As a bonus, it can probably be transposed as it is to your personal symfony application.
As usual, it takes less than one hour to implement, and less than fifteen minutes to read. Enjoy!