[flurdy]

That would be very subjective. But probably exists. I am a heavy user of Twitter's List feature, and have columns in Tweetdeck for friends, local, sports, politics, colleagues etc. And try to curate these for my interest as best as possible, ie weed out too noisy tweeters etc.

I guess you can find other people's lists and follow them? E.g. a sports journalist's sports lists etc. I have not tried to do that so not sure if there are hurdles to overcome. And maybe someone can aggregate these public lists for others to find/follow?