Simply Wood Rings are incredible and the artist seems really sincere and generous.

Another one to look into is Touch Wood Rings (www.touchwoodrings.com). I think the artist is named David Finch. Although very costly, theirs are really admirable.

One more in terms of great quality (and super strong/durable) but also a fair price, is Stout Woodworks (http://www.stoutwoodworks.com).

I think it is really cool that people are looking into alternatives besides common metal wedding bands (and just regular rings). The wood has its own natural beauty that cannot be rivaled by cold metal.