[gnome-love] A good program to write a tutorial about?

[chris <me blixtra org>]

Hi all,

As I posted last week, I'm trying to get my feet wet with gnome and 
would like to solidify may knowledge by writing a tutorial.  So, I'd 
like to get some suggestions on which app I should use for this.  I 
don't want to do something trivial nor too difficult.  I'd also like 
something that uses a good variety of the standard widgits.

Any suggestions?
Chris