This FP column suggests that $40 billion a year would raise the incomes of the poorest up to $1.25/day in 2015. Allowing for poor targetting, that's maybe $100bn or 0.25% of rich country GDP. I responded to some of the comments on the piece here.
An opinion piece for Bloomberg Businessweek arguing that the only moral course is to hire illegals --it isn't bad for Americans and it is great for them, so what's not to love. I talked about it on a few radio stations, including David Serota's show. Immigration does bring out the crazy, but here's a reasonably measured response in the Culpeper VA paper.
Technology and USAID is a CGD essay discussing Raj Shah's efforts to promote technology in development. It is a great idea, but it carries risks well illustrated by his example of a tablet computer changing farming practices and education in rural West Africa.