Gregarius 0.4.0 was just released, and is available from the sourceforge.net download page.
Complete changelog since 0.3.8:
Adjacent item navigation
Logical and operator can applied to tags (a la del.icio.us: /tag/tag1+tag2)
Bug: stripping tags from item titles
Related tags (…)
Tagging: new actions: cancel edit, get tag suggestions from del.icio.us (…)
New option: show only unread items on frontpage
The RSS autodiscovery now works with uppercase <link> tags
Some preliminary cache control (HTTP ETag, Last-Modified, …)
Fixed an ugly bug which would multiply sql-time on index.php by five (…)
I’ve also updated the TODO document to reflect a couple feature ideas I’d like to implement for version 0.5