Are there any good (and possibly free) ways to crosscompile a Java app (using Swing) into a standalone Java or C++ application?

I believe there are free GNU tools for that purpose, and quite a few (expensive) commercial ones. GNU Java is at http://gcc.gnu.org/java/ or you could browse the Google web directory for java dev. tools at http://directory.google.com/Top/Computers/Programming/Languages/Java/Development_Tools/