I've looked and not been able to find an application that does this.
I have many reminders in Tasks and Calendar and if you are in the middle of doing something else and hit 'escape' it will just cancel the reminder....I really rely on these and it would be awesome to have a reminder window/application like in outlook where all reminders get stored until dealt with.
I doubt I'm the only one who would find this useful....when you are multitasking it is a pain to have to open a task or calendar entry reminder and reschedule it on the spot.
Let me know if anyone has seen this or if someone thinks this is worth making.