I'd heard a rumour about a new Google product offering called "Gears" and low and behold I just found Google Reader with a new 'offline' mode:




Google Gears installs as a Firefox extension (no support for Safari but there is Internet Explorer support) and certainly looks like it could be interesting....
The new extension provides Google Reader with offline reading of the latest 2000 posts. Now if only GMail gets the same new treatment...