I suggest distributing the JScience Library in the global maven repository.
Maven (http://maven.apache.org/) is a extremely useful build and artefact
distribution system. You can create new projects easily (including automatic
download of the artefacts) including automated download of the needed libraries;
you have tons of plugins for automated deployment and whatever.
OK, plain Ant has most of this as well, but maven is easier and more powerful in
my opinion. Adding this as a second way of distribution does not hurt, at least.
One might also think about restructuring the project to build with maven, but
this would require changes in the project structure.
If you care I could do both finding out how to get JScience into the global
repositories and, if wanted, restructure the project.