Apart from the known marketplaces (Thingiverse, Shapeways etc.) there are coming more (specialized) marketplaces and it's getting more complicated to find the right file or object to adapt and print.
We created a free search service fabforall.com (at the moment in public beta) that allows to search all the marketplaces at once. We're looking forward to ideas from the community - do you find it useful? What is missing?
Thanks for this!