We definitely want to take advantage of user contributions in some way, but we're still trying to figure out the best thing to do. Also, the app contains several very high-quality images of each species taken in a particular way by a talented group called FindingSpecies, and to keep the visual integrity of the app, we would want very similar photos for all species that we add. This might be difficult to outsource to the crowd.

It's a similar problem to that faced by, say, open source projects that aim to maintain a certain level of code quality and style matching in contributed source code.

Addendum: the image collections of the Australian National Botanic Gardens and the Australian National Herbarium might be of interest to you down the track: http://www.anbg.gov.au/anbg/photo-collection/index.html