World Federative Trade Union?: WFTU vs. IWW
Although the current World Federation of Trade Unions has a bit of undue Russian influence (this from its past Soviet influence) and undue ties to Official Communist parties, I'm leaning towards the idea that a World Federative Trade Union might be more effective in organizing workers worldwide on a "red union" basis than the anti-political IWW:
In January 2006 it moved its headquarters from Prague, Czech Republic to Athens, Greece and now focuses on organizing regional federations of unions in the Third World, campaigning against imperialism, racism, poverty, environmental degradation and exploitation of workers under capitalism and in defense of full employment, social security, health protection, and trade union rights. The WFTU continues to devote much of its energy to organizing conferences, issuing statements and producing educational materials.