Here's an excellent example of a simple to make lamellaphone. The primary element here is an electrician's grounding bar. Combine that with some tempered spring steel, in two widths: 1/8" and 3/16" & you got yourself a lamellaphone (otherwise known as a Kalimba).
Props to Yapruder who came up with this idea. I haven't made one yet, but I am planning to hit the electricians supply store the next time I am in town.
Yapruder has even posted an Instructable build sequence here: http://www.instructables.com/id/Instant-Thumb-Piano%3a-How-to-make-a-set-screw-lamel/
For more inspiration, check out Yapruder's Flickr set online here: http://www.flickr.com/photos/41969054@N00/