Phing is okay, but if you haven’t already, you ought to check out Webistrano. It’s a web-based deployment GUI built atop Capistrano with robust capabilities, including support for passwordless SSH authentication, OS-level atomicity of deployment (change a symlink), catalog of and rollback to previous deployed versions, multiple projects, multiple users, deploying to multiple hosts, database migrations, git, Subversion, and more. Basically, login and click deploy. Really nice. Yes, it is done in Ruby for Rails applications, but I’ve been using it successfully with PHP projects for quite some time now.