I've tried a similar strategy (throwing up a quickie site based on a trending hashtag) in the past by making http://threewordstoliveby.info and http://weedcommandments.com So far it seems that once the hashtag has stopped trending, the sites don't get much traffic. But I suppose it's possible that a hashtag might trend again in the future so I keep them alive. One idea I had was making some kind of automated program to grab the trending hashtags, see if a matching domain is available , make a site from the twitter stream, then... profit?