How to write a simple timed popup reminder script

[Sean Hammond]

Okay, I want to write a script for Ubuntu that will pop-up a reminder
every 20 minutes saying "if someone else is waiting, don't hog the
computer" (exact text to be confirmed). It's for use in a busy cafe
running Ubuntu for free, open Internet access.

Question: What is the best way to do this?

I want to be able to do it as quickly, easily and simply as possible,
so ideally I just want to write a short bash script or python script
which can start on login and run in the background. The notification
itself could be a pop-up window which the user has to close or,
(probably better) it could use the new speech bubble notification
mechanism thing.

I'm happy to write it myself, but don't know how, and don't really
know my way around the platform. Any help? Would this be better posted
to the forums?

Thanks


-- 
https://wiki.ubuntu.com/SeanHammond