Mike Hermes of Okiedoke posts Three steps to solve the immigration problem, along with many others in which he suggests that mandatory national service might serve to provide a path to citizenship for people who have entered the country illegally. He makes some good points, noting:

That’s right; I said everyone. In order to get the benefits of being an American citizen, each person would be required to serve their country in some fashion. This might include working in a hospital, a park, a prison, a school, a library, a charity, etc. And of course, military service would count too.

When completed, a person, and any of their dependents too young, or otherwise unable to complete their service, would be eligible to receive the many benefits of American citizenship.