KDE svn trunk requires [http://www.cmake.org CMake] 2.6.2 since last week. Version 2.6.2 has been released just a few weeks ago, so maybe there are not yet packages for all distros.
So how do you get CMake 2.6.2 ?
Of course you can get the sources (from cvs or as source package from http://www.cmake.org/files/ ) and build it yourself.
But you can also get away with less work and just use the binary CMake packages provided by [http://www.kitware.com Kitware]. You think they won't work on your Linux distribution ? I can tell you, they most probably will. At least I haven't found an x86 Linux box yet where they don't work.
So, here's how you can do it
$ cd $ wget http://www.cmake.org/files/v2.6/cmake-2.6.2-Linux-i386.tar.gz $ tar -zxvf cmake-2.6.2-Linux-i386.tar.gz
And now you are already ready to use it:
$ cd src/my_project $ mkdir build $ cd build $ ~/cmake-2.6.2-Linux-i386/bin/cmake ..
Btw., this way it is also very easy to have multiple different versions of CMake on your system. In http://www.cmake.org/files/ you can still get CMake 2.4.x, 2.2.x and back until the ancient version 1.2.