Fire up Terminal, and enter the following two commands:
cd ~/Library/Application\ Support/TextMate/Bundles
git clone git://github.com/cakephp/cakephp-tmbundle.git CakePHP.tmbundle
Finally, to activate the bundle in TextMate:
In TextMate: Bundles > Bundle Editor > Reload Bundles
This bundle provides a number of snippets for common CakePHP classes. It also provides shortcuts to searching book.cakephp.org, api.cakephp.org and pasting into bin.cakephp.org.