I use a minox III occassionally. Well actually I used to use it occasionally. It sits on my shelf now. I'd sell it but the thing is just so damn cute I hate to part with it. A real marvel of engineering.
I also played with a minolta 16 for a while. That's a little bit better grain-wise but still not very good pictures. Especially compared to an olympus XA which is about the same size.
The nice thing about the minolta is that anyone can develop the film. It's the same size as 110. I always took the film out of the cassette in a dark bag and delivered it to the processor in a black film container.
Goat Hill has a page on subclub.org They provide a wide range of subminiature film. I once bought 100 feet of 16mm from them. THAT will last you a LONG time.
I hold up my hand to having a small collection of 110 cameras. I made a slitter and can now cut down 35mm FP4 and load it in 110 cartridges. Most 110 cameras need the notches that the proper film has, but the small Pentax 110s don't and I've had a lot of fun with those and their interchangeable lenses. Apart from the Pentaxes and a few other up-market models, 110 cameras attract little attention and can be bought for pennies at car boot sales or on any well-known Internet auction site!
Okay, count me in, too -- have three working Minolta 16 cameras, and four cassettes that I've been reloading with microfilm for the past three years (though I used two of the cameras with factory film in the early 1980s).
Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.