Tumblr Simulator 3000
Tumblr Simulator is a bot that posts tumblr meme-ish stuff to its Tumblr blog. It’s also way more popular than I am.
The bot is powered by Tracery and Cheap Bots Done Quick. You can suggest new memes to be added to its templates.
Part of the reason for its popularity is that some of its fans have taken the initial posts and built on the jokes.
There’s also a twitter feed.