One such dying newsgroup is alt.hackers. This group was created in 1990 by Jef Poskanzer, who had the ingenious idea to increase the signal-to-noise ratio by forcing people to figure out how to forge an approved article to post to the newsgroup.
Because of the self-moderation system, the newsgroup has always been one with relatively few, but high-quality, postings.
The group was about finding clever solutions to problems. "Hacker" was once a positive term before the media re-defined it as "someone who breaks in to computers". It meant a smart person who could find a creative solution. A common "hack" in alt.hackers (it got called the "ObHack" by the mid-1990s, in reference to the fact that every posting in the newsgroup was supposed to have one) was to cook a hot dog by connecting it directly to a power outlet, or to fix a car with a tool not designed to fix a car. It could, of course, also be a clever small computer program; many one-line obfuscated programs were the hacks which people posted.
This group probably hit its peak in the mid-1990s; in 1995 the newsgroup had about 70 postings a month. These days (early 2003), the group has maybe 10 postings in a month. The self-moderation system protects the group from most spam; unlike other newsgroup, this newsgroup never got dominated by spammers when the number of actual posters became small enough to have more spam than real postings.
Of course, the spirit of alt.hackers lives on. alt.sysadmin.recovery and alt.tech-support.recovery use Jef's "self-moderation" scheme to minimize the amount of noise in their newsgroups; the blooming open-source movement allows aspiring programmers to improve their coding skills by writing applications used in the real world.
Since the Dejanews archive (which is what Google uses for archives of postings from the mid to late 1990s) for 1995 is very spotty for this newsgroup, I made a 1995 archive available here. This is not as well-indexed as Google's archive, but has some postings which Google does not have.