COMICSHOP  great script for Ircle. includes a nice feature for ops that want to identify bottlers/catchers. recommended. easy to set up and free. tested and working with leopard  
(Version 1.4.2)

NAOH  Makes ircle even better!

Specially now that it autocompletes nicknames based on any part of someone's nickname. (Particularly useful for when nicknames start with odd characters such as { or ~)

I'm sure there are additional features or tweaks that could be added to this script, but I can't think what they might be.

Definitely recommended.  
(Version 1.4.1)

ANONYMOUS  Whenever i type /set, it tells me that permission is denied... annoying or what, it means I can't set any options  
(Version 1.3)

CURRAWONG  This script, like the majority of scripts for ircle, is aimed at a particular network, in this case Newnet (and similar networks with Nickserv and many channels with iroffer bots). It's certainly comprehensive feature-wise, with custom ctcp replies, shortcuts for many common commands, custom auto-away, url logging, msg logging, nick grabbing and much more. It loses points (in a sense) on ease-of-use as there are so many commands and variables, but they are all easily /set, and their settings are viewed in a window with /prefs. It would also benefit the script to have the install/setup instructions at the begging of the readme file. Kudos for having one script for both OS9 and X though. Tested with Ircle 3.1f1.  
(Version 1.3)

HES NIKKE  makes ircle useable!  
(Version 1.2)