A Washington tech start-up says its new portable device can allow restaurant diners do a self-checkout right from their table, rather than wait for a waiter.

About the size of a typical restaurant bill holder, the RAIL -- restaurant slang for "quick" -- touchscreen device from Viableware displays a digital version of the bill, allowing diners to easily split the check among several people, calculate tips, swipe credit cards and print out or email themselves the receipt, CNN reported Thursday.

"Basically you can pay the bill yourself in 20 seconds or less and you're no longer dependent on the waiter," Viableware head Joseph Snell said.

The devices are currently being tested by PayPal and American Express and in restaurants including P.F. Chang's, Dickie Brennan's Steakhouse and pub chain McMenamins.

There are advantages to both customers and to the restaurants, Snell said.

"Since waiters don't have to run back and forth with checks, they can focus on better service," Snell said.