Update: I have corrected some information regarding $KDEDIR on April 3rd, 2009
So you would like to check out the latest Amarok 2 goodness, without messing up your system? One way to do this is by using our
Neon Nightly Builds.
But if for some reason this doesn't work for you, or maybe if you are toying with the idea of contributing to Amarok, here's a simple guide that shows you how to compile and install Amarok 2 in your $HOME, without any danger of interfering with your Linux distro. You can uninstall it anytime simply by deleting the folder. Nice and easy, the way we like it!
This document explains how to install Amarok 2 from SVN in your home directory - in an easy way 
If you already have Amarok installed from your distro, uninstall it to prevent setting conflicts and similar.
Install compiler and KDE 4 development packages:
In Ubuntu, Debian, and all their derivatives:
sudo aptitude install build-essential
sudo aptitude install kde-devel
In Archlinux:
sudo pacman -S base-devel kdelibs kdebase-runtime
In Gentoo:
sudo emerge kdelibs plasma-workspace
Append the following to $HOME/.bashrc:
export PATH=$HOME/kde/bin:$PATH
Reload your edited .bashrc:
source $HOME/.bashrc
NOTE: if you are not using the bash shell, edit your proper shell config file (~/.zshrc or ~/.tcshrc or whatever it may be)
Make KDE aware of Amarok's plugin location:
echo 'export KDEDIR=$HOME/kde' >> $HOME/.kde/env/myenv.sh
echo 'export KDEDIRS=$KDEDIR' >> $HOME/.kde/env/myenv.sh
Create folders:
mkdir $HOME/kde
mkdir $HOME/kde/src
mkdir $HOME/kde/build/amarok
Check out Amarok from SVN:
cd $HOME/kde/src
svn checkout svn://anonsvn.kde.org/home/kde/trunk/extragear/multimedia/amarok
Building:
cd $HOME/kde/build/amarok
cmake -DCMAKE_INSTALL_PREFIX=$HOME/kde -DCMAKE_BUILD_TYPE=debugfull $HOME/kde/src/amarok
make install
Updating KDE Config
kbuildsycoca4 --noincremental
Now you are ready to run Amarok 2, by typing "amarok" in the shell.
NOTE:
If you have installed MySQL Embedded in non-default location (i.e. $HOME/usr),
Amarok may fail to start with error regarding libmysqlclient library. In this
case, add the following string to your ~/.bashrc:
export LD_LIBRARY_PATH=$HOME/usr/lib/mysql:$LD_LIBRARY_PATH
where $HOME/usr is the path you've used in --prefix option.
Have fun