YAI
YAI (You Are Invited!) translates Outlook Exchange Meeting Invitations received in Apple Mail and iCal. It corrects many incompatibilities between Exchange generated invites and ones iCal can accept. As of version 1.4 YAI is now Leopard compatible.
Version 1.4 - 5 May 2008.
Dates to iCal 2
Don't forget another anniversary
Dates to iCal 2 is a replacement for Apple's birthday calendar for iCal in Leopard. It has a range of features to allow the user to choose what, and what not, to sync to iCal from Address Book.
iCal Dupe Deleter
iCal Dupe Deleter is an application to aid the removal of duplicates in iCal under OSX Tiger and Leopard. These are generally the result of a bad sync.
iCal Reply Checker
iCal Reply Checker is an add-in to iCal for Mac OSX 10.4 and 10.5 that gives the user options for how replies to meeting invites are dealt with.
More...Applescripts
Applescripts I have written that others may be interested in.
I'd consider these works in progress and appreciate any feedback. Including scripts to delete duplicate events in iCal and geo-locating the source of emails in Mail.app.