TBO has a story about an organic hydroponic farm that's close enough to encourage frequent visits. Urban Oasis (5416 W. Linebaugh Ave., Tampa, 813-293-3276) is on Linebaugh, right in the path of many folks regular commutes.
I've visited many hydroponic farms, but most are a good drive away from central Tampa, making it difficult to justify for weekly produce. No matter what you think about the concept of hydro farming, it's almost uniquely suited for urban environments since a farmer can get a much greater density of growth out of a limited amount of space.