With the new freeware release Triangle you can share JAVA-Games between your JAVA-phone and other JAVA-phones. Triangle allows you to browse other shared folders and to install downloaded software. With this internet application you can also transfer files from your PC to your mobile shared folder and the other direction.
http://www.muenster.de/~dambergj/triangle.exe

over what ?? BT / IR / GPRS?

costs?