Some of those old phones are nicely slammable.
What's even more bulletproof are vintage street payphones.
Nothing keeps a daily standup call on track like a payphone atmosphere of being on the run. ("Quick, what's sprint status and blockers?! We've got 60 seconds before they complete the trace!")
Add an accelerometer, and you can detect when the handset is hanging from the armored payphone cable, because they dropped it as they ran away. Trigger dial tone sound, to mark end of meeting.
A variation on this theme is using a "burner" flip phone for meetings, so that you can end each one by snapping the phone in half, and stomping the pieces on the ground. Which is cathartic, but less environmentally sustainable.