A Fluid Userscript that adds Read it Later to Twitter
I use and love Craig Mod's Twitter for Minimalists. It is a great way to experience the Twitter web client without some of the cruft. However, the biggest thing I miss from third party apps like Tweetbot is the ability to send interesting links directly to my Instapaper account with one click.
Since Twitter for Minimalists runs inside a Fluid instance I can set custom Userstyles (like Twitter for Minimalists) and Userscripts. I decided to write a Userscript that would parse through every tweet and determine if it had a link and - if it did - append a Send to Instapaper button to the bottom of the tweet. I was able to create the button using Instapaper's iFrame Button API. You can find the the finished code for the Read it Later Userscript here.
Hope you find it useful!