I wanted a simple post expiry plugin for some sites' news feeds: this does what I want. There are no frills and it's missing some extra options (in my opinion), such as excluding/including an entire category, but it works great.
Have tried all the different expiry types and they all have their uses.
Looking forward to a future version with some extra options but, even as it is, it's a real time-saver!
Edit: Upped to 5 stars for version 1.0.3 and later - the new options do everything I wanted. Awesome!