If you want a hint at what may be the "next thing" in tech, just keep an eye on recent filings at the U.S. Patent office.
Of course, most of the ideas submitted for patent protection never see the light of day. Time will tell on this one. But, who hasn't been in this position. You're at a business dinner (or a match.com date) and then there's that squirmy moment when the check arrives. Who will throw down their plastic first? Perhaps a split check down the middle? What about the guy who orders three cocktails and an appetizer with a steak compared to the woman who orders a ceasar salad with a little chicken on top and just water, please?
Big Blue has heard your cries. Enter patent application #7,457,767. IBM is proposing a tableside device that would allow all parties to individually tick off their share of the tab until the bill is totaled out to zero; calculating tax and tip, of course. I wish I had one right now.
There's no guarantee this will ever make it out of the R&D department. For the duration, HP still makes some fine calculators.