一只手机 一台电话

一只手机。 一个电话。

一支手机 一個电话 no people use 一個手機 and i think u can also use 一台電話 i prefer use 一台電話, because it's not small and handy as cell phone : )

一 部/个 手机 一 部/台/个 电话 all above are OK, and 一个电话 ususally means a call

一部手机 一台电话