We last wrote about the Random Hacks of Kindness operation a year ago. Twice a year, a group of programmers gather together for an intense weekend in 28 different cities around the world to benefit some good causes and write some code. Last weekend was the fifth such occurrence, with about a thousand different participants and with more than 90 projects being worked on. That is a lot of hacking going on, almost too much to review in a single article.

And it wasn’t just coders eating a lot of pizza either: the meetups included designers, project managers, PR and marketing professionals and others less tech-savvy. The causes included Doctors Without Borders, the World Bank, Oxfam and even some hyperlocal challenges too.

For example, one hack (which was the winning San Francisco entry) called Drop2Drink included assembling a geo-coded map of the 60-some odd fire hydrants that are used for delivering emergency drinking water in San Francisco in case of an earthquake. The hydrants had small markings on them but no one, until now, had taken the time to do a census and make their locations available online in any meaningful manner. Here is the team hard at work.

This past weekend the organizers tried to encapsulate some institutional memory and use the efforts of prior hacks to help build on new projects. For example, this Philadelphia project drew on what was done a year ago in Bogota, Colombia for locating the nearest homeless shelter based on your current location. And two teams in Portland and Boston were linked together on similar solutions for disaster awareness and helped to reduce duplicated efforts and increase capability for users and help first responders better coordinate their own disaster management efforts.

There are plenty of other examples from cities all over the world that are worth perusing on their website. The next RHOK event is scheduled for June 2012.