My friend Russ Johnson has posted a great tutorial to get MySQL working on Leopard. So you can visit his site or follow the instructions below (so I don't forget)

It seems that the preference pane will not work to start or stop MySQL yet so you will have to start it manually from the command line and create a link to the socket file.

First, start MySQL in a terminal window with the following command:

sudo /usr/local/mysql/bin/safe_mysqld

Then either close the terminal and open a new one, or just hit Command-N to open a new terminal window. Then type the following:

sudo mkdir /var/mysql/

And lastly, create a symbolic link to point the default socket file:

sudo ln -s /tmp/mysql.sock /var/mysql/mysql.sock

I will update this post with info on how to get it going with Lingon