If I learn about a public data set that others might find interesting, how should I let others know? Should I ask a question, such as, "Is anyone looking for outbreak data"?
If it is a portal site, you can post the site to our crowd-sourced catalog of open data portals. There are about 1450 sites cataloged currently.
this is where having a wiki to go along with the forum would be killer. something along the lines of r/datasets on reddit. considering there isn't one here yet, i would post the new datasets there:
If it's research data, I'd also suggest submitting a listing for the archive/repository at re3data, the Registry of Research Repositories.