Ubuntu Repositories lack most recent versions of software

"There are a couple of different options:

Enable the proposed-updates universe on your system via System > Administration > Software Sources > Updates. This will get the newer versions slightly faster onto your desktop. This will only get the minor proposed updates faster, as pointed out in the comments.
Check if there is a semi-official PPA for the software (i.e. maintained by someone from the project team). This is likely to have the latest version of the software, packaged by the team.
Use a PPA maintained by some individual, like you or me. This should be fine as long as you realize you're using a package that was built by an individual and the resulting security implications.

The PPA is Ubuntu's way of providing a viable distribution mechanism to teams and individuals to distribute their version of a software.

The Ubuntu official repository will, and should, contain a version that is tested and stable, and satisfies library dependencies in the system. By it's very definition, it will tend not to have the latest release at all times."

"Ubuntu may not be the right distribution for you. However, you can try to backports repositories. They have more bleeding-edge software, but not each software package in the regular repositories has its own backport.

In short: your mileage may vary, but you should take a look the the Ubuntu-Backports."