We've blogged iCalFix before, back when it was just a fledgling 0.1 release that didn't even have a GUI interface (you had to edit a pref file lying around in ~/Library). For those who don't remember: it's a simple iCal plugin that automatically adds a reminder to every event you create.
In this latest 0.5 release, iCal has become a true-blue iCal plugin, with its own preference pane and everything (As you can see, Robert Blum, iCalFix's creator, is looking for an icon designer. Check his blog for contact details). Now it's possible to specify your own alarm time for new events, as well as which sound to use, right from within iCal's preferences.
iCalFix is donationware and available from Robert Blum's site.
[via Hawk Wings]