This is too funny ... I was yanking up my pants after taking a dump at work just now. I hear another plop.
I say to myself "But I'm done, what the heck was that?"
I look down and behind me. There is the murkiness is.. my.. wallet. Floating on top. And the toilet is one of the auto-flush types. And it's beginning to flush. Without much time to think about what to do - actually that is probably a good thing in this case - I fish it out.
I pull everything out of the wallet - card, license, cash (luckily I have a policy of carrying only a little cash money). Dry each off - the contents didn't get too wet or anything.
Right now the wallet is wrapped in one of those toilet seat liners. So those things actually DO have a purpose.