It’s a newfangled talkie machine thingie that’s so new to the Yahoo! front page team that they haven’t had time to figure out how to spell it.
Some of the folks think it’s a little something called a “cell phone”:
But some others (who I think are just being pretentious) think it’s a “cellphone”:
Maybe it takes a little time for the editors to catch up with technology. Maybe after the cell phone has been around for a few years, they’ll decide how to spell it.