Bubbly gone a little flat? Real Simple recommends dropping a raisin into a bottle of champagne that has lost its effervescence, and letting it sit for a couple of minutes before pouring. The last gasps of carbon dioxide left in the wine will stick to the raisin's ridged surface and release themselves as bubbles.
This trick won't work with a bottle that's been resting in your fridge for a month, but if you're at the end of a dinner party you might get a little more mileage out of your sparkling wine this way.
Raisin as Champagne Restorer [Real Simple]