Good portable stim/fidget toys for adults?

I just finished a long and insanely stressful sensory overload appointment to deal with some government paperwork stuff, and I realized partway in that I could REALLY use something unobtrusive to stim with. Anybody have good recommendations for something small enough to slip into my purse and that wouldn't look far too awkward to use in a public environment dominated by neurotypical people? (I'm not concerned about looking a little awkward, lol, that ship sailed a long time ago)