Self promotion time, I've also written a Jekyll plugin to provide search using lunr.js [1].
[1] Jekyll + lunr.js = Static websites with powerful full-text search using JavaScript https://github.com/slashdotdash/jekyll-lunr-js-search
[1] Jekyll + lunr.js = Static websites with powerful full-text search using JavaScript https://github.com/slashdotdash/jekyll-lunr-js-search
I built my own search on my blog using lunr. It's fast and works great.