Markets are extraordinarily healthy things. They allow small scale, local producers to show their wares – and exist. It would encourage local food growing, local crafts, and local employment. It is undoubtedly the case that people who work in a market are happier than people who work at tescos. Markets allow communities to meet in the fresh air and share their skills.
Every weekend, or at least one day of every week a part of town (e.g. an open square) should become a free market place. Perhaps people should still have to register (through the council) so there is some form of quality control, but the important thing is that a market place should be provided for free, without the need for a traders licence, and that the market should be facillitated (i.e. tables and covers provided).