Woot Wine has a great deal on the Epicurean Wine Preservation System, selling it for only $55, which is more than half off the list price of $120. It'll reseal all kinds of bottles, even keeping your champagne (or sparkling white white for the uncultured masses) bubbly. Its roto-ciprocal (what a great term) vacuum and pressure pump keep the flavor, color, and aroma of your fine swill intact, and comes with its own rechargeable battery. If you drink a lot of wine, and I'm sure you all do, it's a great deal for a pretty useful little product. Woot Wine deals expire at the end of the weekend, so get 'em quick. [Woot Wine]
Nitrogen spray is the best way to preserve wine, as it is heavier than air and will sit on top of your wine so it doesn't oxidize. With a vacuum you'll never be able to get all the air out of the bottle.
I verified this with the winemakers at the Napa Valley Reserve.