I am trying to create a simple project that will turn on or off a 3.2v LED light (latching) by the waving of a magnet nearby. I want to use 2 button cell batteries to power it. Does anyone have a suggested hall effect sensor or durable latching reed switch (not glass because I need it to be fairly rugged) you would recommend? I am not too familiar with all the electrical specs/requirements, so I don't know which one to buy! Thanks so much to anyone for your help!
Hall effect devices are relatively power hungry compared to a reed switch, so I'd use go with a reed switch for battery powered applications. You can get them in small molded plastic or metal housings to make them more rugged.
Here are a few examples:
Digikey stocks several Hall effect sensors that draw in the range of tens of microamperes. They do this by operating at a low duty cycle, rapidly going in and out of "sleep" mode. An example is the Honeywell SL353 series.