I just found this site here:
There you can download many many updated (= new versions!) software packages that did not make it into the repos yet. All the packages are in Debian's *.deb format, so installing is a breeze: Just download the file then double-click on it and tell it to install. Voila, done.
Use this at your own risk. If e.g. the version number of a package is really really still low (e.g. version '0.1') chances are it hasn't been widely tested yet and the application is probably unstable and may cause unexptected crashes or show unexpected behaviour. Also: if the version number of a package is only slightly higher than what you already have (e.g. version '1.1.3' vs. '1.1.5') please think twice if you really *really* need that new version.
I am mentioning the web site here because installing pre-packaged *.deb packages is still hell of a lot easier than compiling stuff yourself.
So the web site 'www.getdeb.net' may be useful to those who really need a certain package, but have had bad luck compiling it themselves and are too unpatient to wait until the package makes it to the Ubuntu repos or onto Mint's software portal ...