Depends what it is, really. If it's something requiring a funny developing process, or something that in the best case would offer nothing different from current films I've got, and/or it looks nice as an intact roll, I'd probably keep it as decor. A roll (or box) of an interesting b&w film, especially if it isn't cool-looking---sure, I'd give it a try. Sometimes it works, sometimes it doesn't, once I discovered that the first few sheets of the box were already exposed but undeveloped and I ended up with someone's photos of the Pacific Northwest taken with a Speed Graphic in about 1950! (Fortunately the sensitivity was shot, so my exposures didn't show up on top of theirs.)

I keep the metal spools too. I don't know why, but it feels wrong to throw them away.

-NT