enFi writes "I want to pay one ISP (only!) for data (only!), and use it for my smartphone and my computer; and until they catch up, I want not to inconvenience the rest of the world — still let them call a phone number. (We all want this, right?) I'm most of the way there: my plan is to get a Clear Spot (their 4G WiMAX coverage is good for me) to use with my unlocked Nexus S (which will only ever use WiFi). I could just use Skype and an Online Number, but talk of Sipdroid+pbxes.org+GV and the recent Google Voice / SIP article make me think I'm only starting to untangle the mess of services and options. Is there a good (not to mention best) way to do this?"