With smoking bans now prevalent in about 70 percent of U.S. cities, it’s not unusual to see bar patrons covering still-full drinks with a napkin to save their seat as they duck outside for a cigarette.

Now there’s something better than a napkin to serve as a seat-saver, and it's also an ad vehicle. It's called the Seat Saver. Think of it as one of those I-wish-I-thought-of-that products.

Nothing fancy here, basically a regular coaster but with a hole in it for looping around the neck of a bottle of beer. Atop a mixed drink, it creates a place for the straw to stick through.

The Seat Savers open up all sorts of creative options when it comes to messages. MatchActivity.com, the dating site, came up with "This seat is taken, and so am I” on one side and on the other “This seat is taken, but I on the other hand …”

Who would come up with such an idea? A bartender. His name is Danny Lane, and he said the idea developed a year and a half ago. "Every five minutes we had to save people’s seats, and it was a real pain."

One day a fellow bartender, hearing him complain, asked Lane, “What are you gonna do, reinvent the coaster?”

Perfect, thought Lane, and in time he paired up with Eric Tecosky, an old family friend, to found Spirited Concepts, and they went on to develop the coasters.

Seat Savers are available through several coaster manufacturers that manufacture and distribute coasters to bars nationwide. In most cases the coasters are given to bars at no cost.

Lane says one big advantage of the Seat Saver is they save bartenders time and trouble, so they're more likely to use them, unlike a lot of the free items bars received.