THIS WORKS EVEN IN QUANTAL (UBUNTU 12.10) 32 & 64 BIT!!!
Never mind the name "karmic-fixes", just create a a new file in your home folder, copy and paste the text below, save the file, make it executable, and run it in terminal.
It will install pidgin, if not installed already, and then all the necessary files etc. to start using pidgin with a rich set of adium styles which can selected from the menu:
Tools > Plugins > WebKit message styles > Configure plugin... and then select from a list of adium styles.
Note: I've written the script below simply by blending edocastillo's script above and h!v's script here: http://ubuntuforums.org/showthread.php?t=1315515.
#!/bin/bash
sudo apt-get install -y --force-yes pidgin libnotify-bin pidgin-dev libpurple-dev libwebkit-dev bzr wget checkinstall
mkdir $HOME/.bin
cd "$HOME/.bin/"
wget --no-verbose -O adium-pidgin "http://dl.dropbox.com/u/422036/adium-pidgin"
chmod +x adium-pidgin
cd "$HOME"
TMPDIR=`mktemp -d`
cd $TMPDIR
bzr branch lp:~pdffs/pidgin-webkit/karmic-fixes
cd karmic-fixes
make
mkdir -p "$HOME/.purple/plugins"
cp webkit.so "$HOME/.purple/plugins/webkit.so"
rm -rf $TMPDIR
gconftool-2 -t string -s /desktop/gnome/url-handlers/adiumxtra/command "$HOME/.bin/adium-pidgin %s"
gconftool-2 -t bool -s /desktop/gnome/url-handlers/adiumxtra/enabled true
gconftool-2 -t bool -s /desktop/gnome/url-handlers/adiumxtra/needs_terminal false
mkdir -p "$HOME/.purple/message_styles"
cd $HOME/.purple/message_styles
wget http://www.adiumxtras.com/download/2160
unzip $HOME/.purple/message_styles/2160
rm -f $HOME/.purple/message_styles/2160
exit 0
UPDATE: If the bzr branch is no longer valid, you can alternatively download the folder "karmic-fixes" from here: https://drive.google.com/open?id=0B7EHkKCNZtpuMWVtUE5hb0pUbkU