I know I can set it in outlook and sync it, and it will have 18 hours on my blackberry as well, but is there anyway to make an 18 hour reminder for new calendar events from the blackberry?

May seem weird, but 12 hour and 1 day reminders are just too far apart, and I need an 18 hour reminder.

As far as I know, not possible. However, let's keep our fingers crossed on 4.2.... but I seriously doubt it as the demand for that feature probably isn;t there yet

I use 18 hours also. For instance, if I am going to a function tomorrow and an supposed to bring something, I usually set the function as a full day event then set the 18 hour deal so it will remind me at noon the previous day to go by the store. I also have all my birthdays set this way so I am reminded to get something BEFORE the day.