I used to throw them away but for the last month or so I've been keeping them. I was asked by our local school if I'd like to come in offer a session on pinball for their "high interest" day. On high interest day the kids can choose from a number of different sessions to get a quick introduction/overview of various hobbies, jobs, etc. If I remember correctly, the sessions are 40 minutes long. I was planning on giving each kid that takes my session a used pinball.
Hopefully, I'll have enough by then (it's happening in May) to give each kid a pinball if they want one.