DIY city= self-empowerment. We have to become the change we wish to see. Frankly, my guess is that the age of the single career is pretty much kaput and people will be taking several odd and part-time jobs, which they might enjoy quite a bit more (variety, getting hands dirty, etc) rather than pushing paper in an office.
The city could be an open platform that connected citizen service-providers and problem-solvers with opportunities to serve. There would be a transparent database of needs of the community, and instruction or guidance on ways to help that situation. SeeClickFix is an excellent model of capturing and making needs transparent from which to build. Cities would extend this to include matching people with particular skills and availability with the right cause. For example, if there is a family that is struggling to care for its children while parents are working, other parents can offer to babysit for the hours needed. If there is a pothole reported, someone from the city can go fix it and report back. Tasks are also tagged related to required skills or experience.
So, there could be physical requirements (strength) and intellectual requirements (marketing) that help direct citizens towards the right kinds of tasks. There could also be an exchange or “trade” for services—e.g. trade babysitting for dog walking, plumbing for legal advice. The platform would go far beyond traditional city services, as this exchange and participation could become a way of life. Ultimately all citizens would have a complete and growing profile of their skills, experience, and contributions in a Facebook-like citizen social network paired with opportunity matching.
The people behind SeeClickFix asked me to put their link on my blog, while I like the idea, seeing that they are already tied to the DMN, I'm not sure my blog would reach that many more people.