GNOME now uses the FreeDesktop.org Trash spec. This means that simply finding and removing old files won't work, as the .trashinfo won't be removed. So I've created a small python script to solve this problem. You can now again create a cronjob to automatically remove old files from the trash.
The new project page: http://logfish.net/pr/autotrash/
Download a snapshot from: http://git.logfish.net/autotrash.git
To get just the script, follow this link:
http://git.logfish.net/gitweb.cgi?p=autotrash.git;a=blob_plain;f=autotra...