Does anyone read these forums who doesn't read lifehacker? this is really nice.

http://www.lifehacker.com/software/quicksilver/set-quick-timed-reminders-with-quicksilver-205244.php

Invoke Quicksilver
Type "." to enter text mode
Type the text I wanted to be displayed on my screen (e.g. call Jim)
Hit TAB
hit CTRL+RETURN (not ENTER on my numeric keypad)
hit Down arrow to display submenu that shows Run after Delay or Run at Time
Hit RETURN to select Run after Delay or Run at Time
Finally, enter the delay (e.g. 3m, etc.) or enter the specific time I wanted the message displayed on my screen.