For all the ruby devs on HN: check out the ruby bindings to qt at http://github.com/ryanmelt/qtbindings. Makes developing GUI apps in ruby really easy. Be sure to checkout the large set of example apps to get started.
I have always looked upon these kinds of projects with interest until it comes to the packaging.
Let us say I create a really super-duper ruby qtbindings application. Is there any way for me to easily package it as a .msi / .dmg / .deb for distribution?
I have messed around with ocra, monkeybars etc and they have never worked or require arcane and undocumented hacks.
Packaging for distribution is the biggest challenge for desktop ruby apps I think.