Sun's CTO for UK and Ireland, Wayne Horkan, is a bit of a Roller hacker, and I mean that in the nicest way possible
His blog has always been a showcase for what you can do with Roller template programming, although recently he has adopted a more simple and clean design. Wayne just posted a set of three interesting and useful Roller hacks on his blog Eclectic
New next-previous macro: this one is useful for showing a reader where they are in a blog, which post they are reading and the names of the next and previous posts; sorta like the "current location" sidebar in Greg Reimer's theme.
Related entries: this is designed for use on an individual entry page and shows entries that are related to the entry being viewed based on tag and category relationships. This is an especially good hack because the code is a little scary; it iterates through the most recent 1000 posts in the entry's category, then the most recent 1000 entries in any category and then it does some analysis. I suspect this gives blogs.sun.com a bit of a workout, but it's serving four million hits/day at 97% idle so that should be no problem, no?
Archive macro: this one shows a blogger.com-like list of links to recent month's entries. Would be a little nicer if it displayed a count of entries for each month, but I don't think that's possible with Roller's current template system and models.
Nice stuff. Have you got any Roller hacks to share?