The Star & Tribune has run a few articles on Minneapolis' testing of new parking meters. The meters give you warnings if you are trying to park during restricted times and they may accept payment via cell phone. The most interesting feature from a traffic engineering standpoint is they can do dynamic pricing – charging more when demand is higher.
Economists and many academics in the transportation field (including David Levinson at the U of MN) argue that "toll roads" are an important tool in managing congestion. There has been significant political and public opposition to traditional toll lanes in Minnesota. The toll lane (technically a High Occupancy Toll – H.O.T. – lane that lets carpoolers in for free) on I-394 has been successful with dynamic pricing and we are adding a H.O.T. lane to I-35W. Adding dynamically priced parking meters on top of the H.O.T. lanes may slowly erode the opposition to traditional toll lanes. Time will tell.