How can developing countries make the most of their diaspora?

Dilip Ratha and Sonia Plaza have a nice article in Finance & Development recommending a number of concrete actions for developing countries, the standouts for me being; 

• developing networks - there is a key role for embassies to play here, who could be doing a much better job at connecting with and engaging their diaspora (can they learn something from university alumni offices?)

• allowing dual citizenship (make coming and going as easy as possible, and people will come more often - currently "only 21 of Africa’s 54 countries allow dual citizenship")

• diaspora bonds (giving diaspora the opportunity to save their money by lending to the government and thus investing in their home country)