I got this idea from Tim Holtz's blog where he shared some pix and organizational ideas from his
studio.
I thought his ribbon storage was awesome, but I just don't have space in my craft room for those shelves, so this is what I came up with:

I got the wire shelves from Walmart and they look like this in the package:
Then I got some threaded stainless steel rods from the hardware store along with some nuts (although these might be unnecessary), and I already had some regular large paperclips as well as clips from my Clip-It-Up that I wasn't using. DH helped me cut the rod into 12" lengths with a hacksaw and then I filed the sharp edges down.
To assemble, I just hooked a paperclip onto each end of the shelving, then clipped a Clip-It-Up clip to the bottom of each one (so the hook end is hanging down), and then hung the rod from the 2 clips. I know this doesn't make sense, so here are a couple close-ups of the whole shebang.
This is how each end looks from the front. You can see the paperclip, then the CIU clip, then the rod hanging from it all. I said earlier that the nuts might not be necessary because the CIU hook holds into the threads keeping the rod from slipping around. I still used the nuts because they covered the raw edges a little for safety.

And here's how it looks from the side (sorry it's blurry - my camera didn't know what to focus on):
So there you have it. It wasn't dirt cheap and it's not the prettiest thing, but I think it will work for all the rolls of May Arts ribbon I've been buying lately!
And one last note: You might be able to see I threaded the ends of the ribbon over and under and over the wire in the shelving. This is to keep the rolls from unrolling on their own, but I can still easily pull the ends and cut whatever length I want. Hope you like my idea!