On the low-tech side, a gizmo that looks vaguely like an upside down skateboard made out of a length of 2x6 wood. It had a slot down the middle and two bars of metal that were articulated in some way that I forget the exact details of now.
You would chop a hole in the ice and push it under the ice, where it floats to the top. There is a lanyard passing through an eyelet in the underside of the "stern" and attached to one end of one of the bars somehow. Give the lanyard a quick tug, and it lifts the bars up without being pulled backwards (this is the detail I forget how to accomplish). When you give the lanyard slack, the bars drop in such a way that a a sharpened end digs into the underside of the ice and pushes the entire gizmo along a foot or so. Repeat this for a while and the gizmo is many yards away. You go to it and chop a second hole near it and drag it out. Now you have a messenger cable under the ice, which you may use to place fishing nets.
On the higher tech side, back in the early '70s one of my roommates borrowed an Arp 2600 Synthesizer (all analog, mind you -
http://www.vintagesynth.com/index2.html ) for a weekend and taught us all how to operate it and get really cool sounds, in about half an hour. We weren't musicians or anything, we were Art students who just liked to play with cool toys. Portable synthesizers were just getting popular among musicians then, so it was still fairly cutting-edge technology as musical instruments went. It was an inspired design, once you got the idea of the vertical sliders doing one thing and the horizontal sliders the other thing. It just made intuitive sense. Many of the internal connections could be over-ridden by a patch cord. Which is why you needed a paper facsimile of the front panel so you could pencil in the slider settings and patches in order to reproduce the same effect at some later time. This then leads to the notion of a "patch change" as a name for a type of MIDI event, because changing a synth's sound used to often involve actually inserting or moving patch cords.
Sadly, the only ARP 2600 emulators for Macs require $$$ to obtain.