Yeah Python is probably your best starting point, if you're comfortable with it (who isn't?).

I'd take a look at Quickly. It's there to get "opportunistic" developers writing something as soon as they possibly can. As such it lays a lot of the groundwork for you, as well as giving you a good basis for getting it packaged and on Launchpad for release.

sudo apt-get install quickly quickly-ubuntu-template

cd ~/Desktop # optional

quickly tutorial ubuntu-application

But that'll get you started. I would really recommend going through the tutorial but the main steps are:

quickly create ubuntu-application myapp

cd myapp

quickly edit # opens in gedit

quickly design # glade UI designer

quickly run # run it

quickly package # package it

quickly release # push it all to launchpad (you'll need to do some setup)

I think you'll agree, this makes it disgustingly quick to write, design, test and publish an application.

There are other templates available too for other uses (CLI apps, etc).