Aptana is a pretty good IDE (http://www.aptana.com/) based on Ecplise.
The great thing is that it works with cakePHP.
Just one thing is that cakePHP v1.2 have the views with a ".ctp" extension and Aptana does not handle the code colouring, etc. Luckily this is an easy fix:
Click Window->Preferences...
Select General->Editors->File Associations
Click the "Add.." button and add in *.ctp
*.ctp will appear under "File Types". Click on *.ctp and click the "Add.." button for Associated Editors. Select Aptana PHP Editor.
Done.
