Are we about to have another national carrier on our hands? MetroPCS has put together a $5.3 billion stock swap offer for Leap Wireless -- perhaps better known for its Cricket brand -- potentially pairing two regionals to create the nation's fifth-largest carrier, displacing Alltel in the process and combining regional licenses to create a rather generous coverage footprint. Of course, this is all based on the assumption that Leap's cool with the plan; at this point, all we know is that MetroPCS sent a nice little letter to Leap's board of directors. If everything goes according to plan, though, and the appropriate regulatory bodies approve, expect the two to close on the deal in spring of next year.