The system isn't perfect. Robocalls do slip through. Foss encourages subscribers to report those numbers so they can be added to the list. It's crowd-sourcing to stop illegal telemarketing.
Nomorobo expanding ... sort of
Anyone with phone service from Comcast and Time Warner Cable can now use Nomorobo. The two cable giants started offering Nomorobo a few weeks ago because they know their customers hate robocalls.
"We are excited about providing our customers with another alternative to block telemarketers and robocalls," said Patti Loyack, vice president of broadband voice for Comcast cable.
(Disclosure: Comcast is the owner of NBCUniversal, the parent company of CNBC and CNBC.com.)
Jeff Lindsay, general manager of Home Phones at Time Warner Cable, said, "The last thing we want is for someone to have their enjoyment of our service affected by these nuisance calls."
(Read more: Consumers have had enough, 'rage survey' says)
Nomorobo still does not work with any traditional landline phone service because they don't offer the simultaneous ring feature it requires.
The landline companies say they support Foss, but are limited by their older technology.
"It would be like trying to provide digital service on an analog TV. It just can't be supported," said Kevin Rupy, director of policy development at the United States Telecom Association (USTelecom).
He said traditional phone companies have to be very careful about how they address the robocall issue, because they are governed by regulations that do not apply to cable companies and other VoIP phone services. For example, the FCC requires them to complete all calls and specifically prohibits them from blocking any calls.
"We're not kicking the can down the road, we're not punting on this issue, but we have to be very cautious about how we implement any type of service like this," Rupy said. "It's an extremely complex technological and legal issue."
The industry is making a massive and expensive switch to Internet-based voice technology which would support a Nomorobo-type service. Rupy points out that many phone companies that offer VoIP service (such as AT&T U-verse and Verizon FiOS) are already compatible with Nomorobo.
He said phone companies are working to create standards that would solve the robocall problem for all types of telecommunication networks. "There is hope" for people with landline phones, he said, but a solution is probably one to two years away.
(Read more: Hate robocalls? Here's how you can block them)
Sen. Claire McCaskill, D-Mo., chairwoman of the Senate Subcommittee on Consumer Protection, doesn't want to wait that long.
"It's time for the telecom industry to do its part to help combat illegal robocalls," McCaskill said in a statement. "Nomorobo and other technologies offer consumers greater options to combat this problem, and it's disappointing that these solutions have not been embraced by our phone companies."
McCaskill said it's become clear that Congress must act to "provide regulators with a robust set of tools to fight these fraudsters." She plans to introduce legislation to do that in the coming weeks.
Note: Nomorobo does not work for wireless phones, but there are a number of robocall blocking apps are available for Android devices, such as PrivacyStar, mrnumber and Blacklist Plus.
—By CNBC contributor Herb Weisbaum. Follow him on Facebook and Twitter
@TheConsumerman or visit The ConsumerMan website.