I have to report that after doing some more research on hermit crabs, I have learned that you really don't need to have just one because they're very social creatures.
I've been worried about Bart, because he (I've changed my mind and now believe he's a HE, don't know why?) has been pretty motionless, like all day long, sometimes so much that I turn him over (so he'll have to turn himself back over - they don't like to be on their back) to see if he's alive. In the mornings I can tell he's climbed around some because some of his "toys" will be moved, etc...
Anyway, I was feeling guilty so I went to the pet store last night and bought him a friend! And OMG. I wanted to get one that was really active, to hopefully bring Bart out of his shell, so to speak 
. The pet store employee lifted a large rock and several crabs were under it and this one just hopped right up and started practically running around to the back of the cage and up the side, like lickety split! So I said, "I want that one!!!!" The girl grimaced, like, "Oh man. Are you SURE??" haha Because he isn't one of these that shrinks back in his shell when you pick him up like most of them do. And I think she was afraid she'd get pinched.
I bought some more sand so they can burrow better, a few empty shells (because apparently they like to swap shells with each other and with random empty shells), a bottle of saltwater they told me I need - because they should have one bowl of fresh water and one of salt water (WHO KNEW??), some other various toys and stuff and headed home. This little guy (he's actually a little bigger than Bart) scratched and climbed around the little cardboard box they send him home with the whole ride home, claws sticking out the side, etc... it was hilarious.
When I got home, Bart was motionless as usual. I cleaned out his cage and put all the new stuff in then put Bart and the new kid in. Well, as expected, the new guy proceeded to run around the cage top to bottom, side to side, checking everything out. Then after about a minute, Bart started coming out of his shell!! We couldn't believe it. He's been so shy if people are around; he's such a fraidy-cat that he never comes out unless he thinks no one's looking... anyway, he made a bee line to the saltwater bowl and drank and drank and drank - I felt so bad! He wanted that saltwater! Then he just crawled up in the bowl and sat playing, moving around, drinking, etc. for almost 2 hours! He wouldn't come out of the saltwater bowl! haha Meanwhile, Speedy G is continuing his laps around the cage. Finally after a couple of hours Bart exited the water bowl and started interacting with the new guy. They haven't fought yet, although I hear that's normal.....
When I got up this morning their cage looked completely disheveled, like they'd continued their romp all night long. It was hilarious! I'm so glad Bart is active now -- I still don't know if it was the addition of the salt water or the new friend, but he is in hog heaven.
I will take pictures soon and upload them.
"We play so fine, don't you agree?" ~ Layne Staley
"We want to celebrate what we did and the memory of our friend." ~ Jerry Cantrell