Deceiving your players

All you need is something that looks innocent and you can keep the players distracted long enough to put them in a tidy pickle. Much like the monster in today's motivator that's going to sink the boat while they all look at the fake dolphin on its tentacle.
This reminds me of a classic deception I pulled on my players. They were all performers in this particular campaign and as part of an information gathering mission they infiltrated a party. Unsurprisingly they ended up performing for said party. Towards the end of their performance at the party they were found out. Rather than making a mad dash for the exit, they opted to waltz their way out the front door. Their exit performance went well until they were stopped by a tiefling. Of course I didn't tell them she was a tiefling, I just gave them a general description of her vaguely demonic features. She then handed them a magical purse and let them leave.
My players spent the next hour trying to figure out what the magic was on the purse (none of them had identify, but several had detect magic), up to and including dumping the contents on the street in the middle of the night to reveal 2000 gp. The tiefling was the lady of the house and she gave them a small bag of holding with money in it to pay them for the excellent performance as the performers scheduled for the night had not shown up. Using a little misdirection and misinformation, I managed to have them all quite freaked out by the situation. It was a blast.
So let's hear your awesome stories of misdirecting or being misdirected while playing RPGs.
LooneyDM is listening.