Instascriber – Subscriptions For Instapaper
http://www.instascriber.com/

Instascriber makes it easy to subscribe to your favorite RSS Feeds and have them automatically appear in Instapaper. Simply log in to Instascriber with your Instapaper credentials and enter the RSS Feeds you would like to appear in Instapaper. Instascriber will automatically add new items to Instapaper as they are published. This has been added to the tools section of Research Resources Subject Tracer™ Information Blog.