Chris Pirillo’s Gaba.be continues to roll out new features weekly. They’ve also made a change to the URL structure for tag queries to become better indexed by search engines.
This tag based search engine is still somewhat under the radar for many people, but it is quickly becoming one of my most-used sites for research. It’s also the best place I’ve found to do cross-application photo searches.
My original profile of Gada.be is here.