I never understood the bags either but it seemed like a good staple. However I'm against the useless junk idea for the contents of the bag though. Perhaps something useful would be good.

Try to pick items that go with the theme yet are useful. Perhaps you could find some martial arts themed notepads and pens? Something that's cheaps and may be bought by the bulk. Keychains and little trinkets that can be hanged and used as decors on a cellphone, ipod, bag, etc can be done as well.

Make it thoughtful yet unique.

The problem with cheap technological gadgetry is they die off quickly. But I'm for the USB thumb drives by the bulk sort as gifts. They seem good enough.