I definitely do the "want to share but also 'bookmark'" thing with my Twitter updates. And, yes, hashtags somewhat solve this, but not really - at least not for me. I like the idea of lists on Thingist, but I don't want to have to categorize all my tweets.

If Thingist could automatically categorize my updates, but have a way for me to re-organize them, that'd be ideal. Seems like a decent amount of people fall into your same use case, where they tweet quotes, songs, videos, etc. Some of these would be easier to detect than others, but it's somewhat doable.

This seems some like weird cross section between Twitter, Tumblr, and delicious to me.