Considered one of the Holy Grails of J2ME programming, self-replication is a must for viral marketing by helping your product spread quickly. It involves two parts: getting your hands on the jar and sending it via Bluetooth OBEX.

Retrieving the JAR contents is cumbersome, it involves re-packing the JAR or hacking the ZIP structure (an excellent paper is this one). As for OBEX, most phones don’t support it natively (the API) so you’ll have to implement it from scratch.