I want to upgrade an application that I have on Ubuntu Server 8.04. I see that the version of the application I want is available under Ubuntu 10.4. Is there a way that I can get just that application (and its dependencies) to upgrade to the newer version under Ubuntu 10.4.
You can't upgrade your application just by switching some flags on. It would require to update every dependencies to the new version and that might make your system unstable (or simply broken).
What you can do is look at backports. These are newer versions of some packages that are compiled against the current library for your system. Not every packages are backported but with luck, you will be able to find a newer version than on the stable repository.
Another option is to work around the package system and install the application and its dependencies manually by compiling it. It may be painful and will not allow for an easy upgrade so keep that in mind before going this way.