There are lots of computers that get tossed here in the US .. A foundation would allow you to approach companies to set these in far away places and pick up the freight tab as a donation. Intel and other large US companies also donate stuff... Bill and Melissa gates foundation donates stuff... although the thought of them donating boxes to run LINUX on might not seem appropriate...
Anyway bottom line... having a foundation or non profit corp. in the US you would be able to offer US companies and US citizens tax incentive for helping..
Sad to say ... most of the time if there is no tax incentive they will do nothing.
OK now for the legal parts...
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If you are going to incorporate in just one country II would incorporate the foundation in what ever country would offer the best donations, as you will have to be incorporated in that country to offer the citizens the tax benefit. The US with the abundance of technology stuff here seems to make sense. But you can also incorporate it in many countries just like you do a corporation for profit.