I am a pocket knife guy,from way back. I got my first pocket knife when I was five years old, and I have carried one, ever since. I snuck around with my knife in grade school(s), and actually got a pass to carry one in highschool.
When I first worked in a warehouse, I saw a need for a knife I could open with one hand. I would hang from a warehouse rack, pull out a box I needed to open, and then fumble around trying to get my knife open so that I could cut the tape.
It was at that time that I finally justified buying myself a switchblade.
The bicycle equivalent of a switchblade is a LandRider auto-shift bike.
If you have insomnia, you have probably seen the LandRider infomercial. The makers claim that it is a pro-level racing mountain bike, and the answer to the prayers of all those who are too uncoordinated ot stupid to learn how to shift a real bike's gears.
We got a couple of these "bikes" in for repairs during the time I worked at Destinations Cyclery. Not only were they crap bikes, but the auto-shift mechanism was, at best, randomly effective.
A $3.00 ebBay switchblade is more effective than these bikes. And, it would be way more likely to entertain a bike shop mechanic..