I happened upon this product from a company in Japan (Mame Design) a few years back. Even though it's much too small for my tank & quite costly to boot, I was intrigued by the simple but fine craftsmanship of this little wooden air stone driven glass skimmer. I have a thing for wooden air diffusers, since my own skimmer uses them as well. I find they produce the finest bubbles I've seen & replacing them from time to time is not a big issue for me.
The company also makes really nice overflows & several other aquarium items. Not sure how many of their products are available in our part of the world, but these days with a little persistence & the help of the interweb, I'm sure it's possible to get one.
http://mame-design.jp/aqua/goods/aqu...skimmer3.shtml
http://www.nanoreefblog.com/reviews/...xed-and-tested
As mentioned, their stuff ain't cheap, but they look like little pieces of art in glass, so kind of worth the money if you appreciate this on items that are functional as well. I suppose you could DIY something similar in acrylic or even a small glass bottle. Would be perfect for a 5g.