This is a quick post, which I hope may help anyone else trying to install MySQL, but I have not gone in depth on any of the steps. If you have any issues or questions, please feel free to comment below.

Disable any existing installs of MySQL:
sudo rm /usr/local/mysql

Remove the startup item:
sudo rm -rf /Library/StartupItems/MySQLCOM/

Setup your path by editing your .bash_login file, I’ll be using Textmate:
mate ~/.bash_login

Add to the end of the file:
export PATH="/usr/local/bin:/usr/local/sbin:/usr/local/mysql/bin:$PATH"

Save the file.

Create a directory called src in your home folder.
mkdir src
cd src

To download the mysql source:
curl -O http://mirror.provenscaling.com/mysql/community/source/5.0/mysql-5.0.45.tar.gz

Extrace the code from the gzip and enter the directory:
tar xzvf mysql-5.0.45.tar.gz
cd mysql-5.0.45

You now need to configure MySQL, paste the following into Terminal and press enter:
CC=gcc CFLAGS="-O3 -fno-omit-frame-pointer" CXX=gcc \
CXXFLAGS="-O3 -fno-omit-frame-pointer -felide-constructors \
-fno-exceptions -fno-rtti" \
./configure --prefix=/usr/local/mysql \
--with-extra-charsets=complex --enable-thread-safe-client \
--enable-local-infile --enable-shared

Now we will compile the code:
make

And install the code:
sudo make install

The last two steps may take a while.

Once all of this is complete, it’s time to setup the initial database user and privileges.
cd /usr/local/mysql
sudo ./bin/mysql_install_db --user=mysql
sudo chown -R mysql ./var

Now MySQL should be installed. In order to start the initial MySQL and have it start every time you restart your machine, do the following:

Create a file in /Library/LaunchDaemons named com.mysql.mysqld.plist
Paste the following XML into the new file:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>KeepAlive</key>
    <true/>
    <key>Label</key>
    <string>com.mysql.mysqld</string>
    <key>Program</key>
    <string>/usr/local/mysql/bin/mysqld_safe</string>
    <key>RunAtLoad</key>
    <true/>
    <key>UserName</key>
    <string>mysql</string>
    <key>WorkingDirectory</key>
    <string>/usr/local/mysql</string>
</dict>
</plist>

While still in the LaunchDaemons folder, enter:
sudo chown root /com.mysql.mysqld.plist
sudo chown root com.mysql.mysqld.plist 

Return to the top directory and enter:
sudo launchctl load -w /Library/LaunchDaemons/com.mysql.mysqld.plist

MySQL should now be running. To enter MySQL, enter in Terminal:
mysql -u root

You should see the following:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.0.45 Source distribution
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql>

Congratulations, you’ve installed MySQL from binary source!

If you do not see the MySQL monitor, make sure you followed all the steps above. When I did this for the first time, it didn’t work so I disabled the install and started over from the top and it worked fine the second time around.