Update:
I went through the various pointers people gave me, and after a "camcontrol rescan", I can now see the flash drive. Or rather, a flash drive. The drive I generally use still isn't visible in FreeBSD, but other ones are. That says to me that something is wrong with that particular flash drive. I'll clean it out in Windows-XP, then try to reformat it. If that doesn't work, then I'll just replace it. Those things aren't that expensive, all things considered.
Still, I can now probe and mount other flash drives using the manual mount procedure, which is what I was after in the first place. Note that before I went through all of this, my system couldn't see *any* flash drives, so your pointers ultimately did work.
It looks like the FreeBSD portion of this problem has been solved. That being said, I want to thank everyone for their help and pointers.
RJPugh