That's not at all what I was looking for, let me rephrase the question.
In v3.x of Eclipse, when I click on a build.properties file, I get a dialog that specifies an interface where I can select which files/folders to include in the build, etc. Even when I right-click on the file, there are options to:
* Ant Build * Ant Build...
The one with the "..." is what i normally run using my build.xml, the other one gives the interface I referenced above. After using Ant for some time, I'm comfortable modifying the XML, but if I could just checkoff the files/folders I want to include, that would be even better!