I finished the bottle of 2005 Ravenswood Sonoma County Zinfandel last night. Alas, it wasn't as exuberantly fruity and intense as it had been Wednesday night. As is often the case, a day open in the bottle did it no favors. It improved as I got down to the very end of the bottle, but it was no match for what it had originally been.
I typically use those little Vac-u-vin rubber stoppers that allow you to pump the air out of the bottle and form something of a vacuum when I have a portion of a bottle left that I'm not going to finish that day. It works reasonably well, I suppose, better than just putting the cork back in the bottle upside down. But I don't think that I've ever had a wine that tasted as good on the second day as on the first. Air just doesn't do anything positive for wine in the long run. I read about wines that have to be decanted and left to sit for hours before they begin to open up. I evidently haven't been drinking that kind of wine.