Dancing Raisins

When a base and an acid mix it makes a gas.
If you put the raisin in the gas (which are the bubbles) the gas will stick to the ridges on the raisins.
The raisin will float to the top and the bubbles will pop.  It goes back down and collects more gas.
It will keep happening until there is no more gas.
Robert

The vinegar fizzed because a Base and an Acid were mixed together to make gas.
The bubbles stuck to the raisins because the raisin were wrinkly.
The raisins danced in the vinegar because the bubbles stuck to the raisin and lifted them to the top. Then the bubbles escaped from the raisins and the raisins sank to the bottom to get new bubbles.
Lauren

Vinegar is an acid and bicarbonate of soda is a base.  When acids and bases mix, there is usually a reaction.  In this case there is a reaction.
The reaction is the vinegar starts overflowing and the bubbles start fizzing.  
If you put raisins in the vinegar they will sink to the bottom of the cup.  Then the bubbles lift the raisins up. But when they evaporate (the bubbles) they will sink to the bottom again. The raisins will do this a lot, it will look like they are dancing.
Aidan

The raisins dance because of the bubbles that nest in the holes of the raisin.  The raisin is heavy enough to carry the bubbles to the bottom.  But if there are to many bubbles, the bubbles will lift the raisins up and pop.  Thereby making it fall and do the circuit again. 
If there is a lid keeping the carbon dioxide in, it'll go boom and shred the cup to pieces.
Ian

Vinegar, Raisins and Bicarbonate of Soda

Overflowing!

Wait for it!

Off they go!