Is there any way to know how much power a device is actually using
within NetBSD? I have 2 USB ethernet adapters, and I want to know how
much power they are drawing. Short of making my own adapter and
putting an ammeter in there, do I have any options? I suppose I
wouldn't be too opposed to using a tool available for (gasp) another
OS...

I can look up specs, but that's not the kind of info I'm after.

And as a side note, does anyone know of any USB ethernet adapters that
are particularly low on power requirements?

Thanks.

Andy