I'm using that more than my blog. It basically sub-divides my public postings. I have 'earthquakes', Linux, and Grouchy. People can turn a collection off. I've been criticized that my blog wanders all over the map, so maybe we need sub-headings for this as well.
For instance, I put a comment on the recent Nepal M7.3 on collections. It's not really an aftershock, but a quake that is marching down the line. I might give up on the blog, who knows?