A long time Gnome user has finally been converted to KDE. I love KDE 4.2.90!

That being said I am trying to learn the new interface and I have tried to install new apps I have run into an issue. There are I lot of 3.x apps and I am not able to install them because the 3.x libs are not present. I know that I can use the package manager in Kubuntu, but I am referring to compiling apps from source. It there a work around for this problem until the developers have the apps I am interested in port to KDE 4.x? I have searched for tutorials on how to install KDE 3.5 to coexist with 4.2.90 but I do not really want to install the entire 3.5 desktop.

Any suggestions would be appreciated.

Compiling from source is very easy to do with kdesvn-build. It can compile either KDE 3 or 4 in a separate directory. Some KDE 4 users keep a copy of KDE 3.5 this way.