Using flashdist is a quick way to create OpenBSD based test environments on flash systems. It works well in an environment for production systems that will experience frequent, partial changes (new kernels, new daemons, etc). It's also for people getting their feet wet with small systems in general.
flashrd:
This is the successor project to flashdist. Check it out. The FAQ explains its advantages over flashdist.
others:
There are lots of cool packages out there that are flashdist inspired and others like flashboot that are completely different. I'm glad that people think it's a useful idea. But, I'm not listing them here anymore because I don't keep track of them.