Make notifications repeat until dismissed

[#1]

I use the Calendar application often. I set up reminders for tasks. When the task is scheduled, a reminder pops up, and the phone rings. Is there a way to make this ringing repeat (say, every 5 minutes) until I dismiss the reminder? The reason is, if I go out and the phone rings while I'm out, there is no visible indication that something happened while I was away. The screen is blank and the LED is not flashing. So I have to activate the phone and manually check whether there were notifications while I was gone.

[#2]

You might be better having a look on the Android Market for a calendar app that offers an LED notification.  The stock calendar app doesn't give you that many options.  I use an app called Jorte which I prefer looks wise but I have just checked that and it doesn't appear to have a setting for LED on it.