Standard MySQL 5.5 installation on debian using dotdeb

On debian the fastest way to setup MySQL 5.5 is just the following:

nano /etc/apt/sources.list

# for mysql 5.5
deb http://packages.dotdeb.org stable all
deb-src http://packages.dotdeb.org stable all

wget http://www.dotdeb.org/dotdeb.gpg
cat dotdeb.gpg | apt-key add -
apt-get update

apt-get install mysql-server-5.5

Now check your phpMyAdmin or similar management tool to see if the correct version is being reported (or use mysql -v).