Hybrid Community Networks?

CaryMenage asks: "I live in Philadelphia where there is a chock full of row houses and MDU (Multiple Dwelling Units) buildings. I was wondering if other Slashdot readers have been involved with community networks and what methods they have used. I have been looking at several different ways to distribute a T1 circuit to multiple end users; WiFi, Powerline, HomePNA. Due to the physical and legal complexities of older buildings and crossing public streets, I feel that some type of hybrid mixture of different topologies would work well in many situations. Has anyone implemented any of this on a large scale installation?" "I currently let my neighbor access the Internet through a powerline device that works well through the power meters. It seems to me that in theory, one could repeat the Ethernet with a cheap switch and send it to the next neighbor with another pair of powerline devices. Then when you have to cross a public street one could use a pair of Wireless Access Points in bridge mode. I also found a "leaky coax" product called RADIAX that I was wondering if anyone has applied this to 802.11. Seems to me you could use this coax and amplifiers to expand wireless coverage within buildings. For apartment buildings with somewhat organized main phone closets I have been looking at HomePNA products like the Xterasys HSM-1402 14-port HomePNA Switch and the Xterasys VX-110B for the end users connection."