Can I save my starter I didn't use?
 

I made a starter yesterday from some washed yeast I had and kept it in a growler overnight, shaking it wheneve I walked past. I had some equioment manfunci0ns today and never got around to using it. Can I save this yeast for another day somehow or should I just throw it out? I'd like to save it since it's my last batch of this yeast type I have saved. Any thoughts?

Wash it and put it in the fridge for the next time. There's a procedure on here somewhere for washing yeast simply with water.

Put it in the fridge, I think you could save it for at least a week before either using it or washing the yeast to save for later.

Just stick in the fridge. It will settle out and you can decant the excess liquid from the yeast and just pitch the slurry. Should be perfectly good for a week or two.

+1 on stick it in the fridge. yeast are not one shot wonders.