Ahhhh clip on...don't know how I missed it.
Hmm, never thought about the snap-on type Vox, didn't know they existed...I've seen clip/squeeze on lens converters. I guess if you're looking travel light and compact (w/o the tube). I personally like the idea of leaving the extension tube and UV/Skylight filter on to protect the lens and zoom barrel mechanism. But that's just me. Besides, I already have 55mm filters, so I guess that's where I'm coming from. It's all about me! :lol: kidding.
I did a quick search for filter clip on holder/adapters, and found Cokin filters. It looks like it clips onto the lens. Not completely sure about it.