In the EA movement, there's a lot of enthusiasm for significantly increasing the number of immigrants able to come to countries like the United States each year. This would help the global poor in two ways: it would directly help immigrants who come to rich countries but wouldn't have been able to without the policy changes, and it would help family members of those immigrants who remain in the home country but receive remittances.
But lately, I've been thinking a lot about other policy changes on the part of rich countries that could greatly benefit poor countries, ones that don't get discussed as much in the EA movement. Some ideas:
Increasing government aid to poor countries: This is kind of obvious, and I suspect many people dismiss it on the grounds that most voters wouldn't support it. But the President's Emergency Plan for AIDS Relief under George W. Bush suggests that efforts in this area may be more feasible than commonly assumed.
Debt cancellation/creating a global bankruptcy process: It might be tempting to assume that it would be easier to get money for, say, programs to combat disease than it would be to get money for outright cancellation of the debts of poor countries. On the other hand, the fact that many poor countries have debts that were originally contracted by corrupt dictators creates a moral case for debt cancellation that many find compelling.