We've been playing with Kodak's Ektascan Xray film. Cool stuff. It has a tabular grain (rumor is that it's the same emulsion as their TMax but without the panchromatic dyes) and is single sided. And cheap, about a buck a sheet for 8x10.
Of course, it's orthochromatic and we were curious about its spectral response but couldn't find anything definitive on the web. So we did a quick test. Here's the standard Macbeth color checker as seen by Ektascan (we added the labels.)
In case you forgot, here's the color version:
As you can see, (unless you're color blind), Ektascan doesn't see much difference between red and black. This also gives you a rough idea of how various other colors will map to shades of gray. Of course, things will look different on your monitor.
BTW, in the photo of the pond and cell tower, the "ice" on the lake is actually bright green moss.
We're still experimenting with processing it in our SP-76EC. So far, a ratio of 21+1 for 15 minutes with limited agitation seems to be working well. We'll have more data soon.