Raphael Stolt published a method to get a visualization of a Phing buildfile a few days ago:
Out of the box the Phing -l option can be used to get a first overview of all available targets in a given buildfile but it doesn’t untangle the target dependencies and sometimes a picture is still worth a thousand words. Luckily the Ant community already provides several tools to accomplish the visualization of Ant buildfiles, reaching from solutions that apply a Xslt stylesheet upon a given buildfile.
He uses the ant2dot tool and the Graphiz library to show the XML from a buildfile into a graphic. The image represents the flow of the build.