[sp332]

The most efficient way to help homeless people is to walk up to them on the street and give them money. Not much room there for innovation. On the other hand, the cheapest way for society to help "permanently" homeless people is to pay their rent on an apartment. That might be more interesting.

[chopsueyar]

Give them anything but money.

[sp332]

It's a small pilot project but it went really well: http://www.economist.com/node/17420321?story_id=17420321

And, with the standard Malcolm Gladwell disclaimer, http://www.gladwell.com/2006/2006_02_13_a_murray.html seems to indicate than most homeless people aren't homeless for very long.