I've looked everywhere for a feature like this. I use the Aptana IDE (which is based on Eclipse) for my php development, and I use the outline feature a lot.
I enjoy xcode's 'pragma mark' feature, which lets you group sections of your source code together in the outline view for quick reference. (Described here: http://cocoasamurai.blogspot.com/2006/09/tip-pragma-mark-organizing-your-source.html)
Is there anything like this for Aptana/Eclipse?