Treehugger has a video review of the "Torqeedo" electric outboard motor. It sounds a bit whiny, but certainly no more garish than a gas outboard. Each charge of the Torqeedo's lithium-manganese battery is good for a range of up to 10 miles, depending on speed and model.
It looks like the "Base Travel" variant can be picked up for around $1,200 online.
Testing the Torqeedo Electric Outboard Motor [Treehugger]