The setup for Ubuntu 11.04 almost identical to the 10.10 setup.
First, install the necessary packages and a system Ruby (1.8.7). RVM will ignore the system installed Ruby, but in my experience you will save yourself a lot of hassle by having a system-installed Ruby.
sudo apt-get install ri ruby ruby1.8 ruby-dev rake libruby1.8 zlib1g-dev libssl-dev libreadline5-dev libncurses5-dev build-essential curl git-core git-gui gitk libxml2 libxml2-dev libxslt1-dev bison autoconf
Then install RVM (see the RVM website for the latest installation instructions).
bash < <(curl -s https://rvm.beginrescueend.com/install/rvm)
Then run the following command, and… READ THE NOTES!
Make sure you read the RVM post-installation notes. You will get an updated list of OS dependencies and instructions on how to modify your .bash file. If you don’t do this you will probably drive yourself crazy trying to get RVM to work. You will fail.
Finally, install whatever rubies you want:
rvm install 1.8.7-head rvm install 1.9.2-head
Then install MySQL (and the MySQL GUI tools)…
sudo apt-get install mysql-server libmysqlclient-dev libmysql-ruby mysql-admin