Edible plants generally have good sources of information online, and the banana is no exception. I’ll step aside today and guide you to two excellent references: for a quick overview, read Musa from Cornell University; if you’d like to read about bananas in detail, spend some time on Mark Rieger’s Banana and Plantain page, part of his comprehensive Fruit Crops site.
From what little I know of identifying bananas, I think it’d be particularly difficult (if not outright impossible) to pin down the precise name of this banana from the photograph. Examining Mark Rieger’s site suggests that some crucial missing pieces of information include the sweetness of the banana and the thickness of the berry’s skin. At the very least, it is certainly something of hybrid origin and cultivated – the native distribution of edible Musa species is southeastern Asia to northern Australia.
Agriculture / conservation resource link: Saving the Bottle Gourd from the New Agriculturist; Lagenaria siceraria is estimated to have been in cultivation for over ten thousand years, but indigenous knowledge of the plants is being lost with the use of plastic containers and changing diets. How to stop the loss? A Gourd Museum. Discovered via the IPGRI Public Awareness weblog – listen to an interview with people involved in creating the Gourd Museum here.