The correct way to break into a QSO in progress is to tune up your amp to 2500 watts, turn the mic gain up until everything distorts and you send harmonics up the entire band and then yell your call sign into the mic.
Seriously, just wait until there's a lull in the conversation then transmit your call sign. Also, in ham radio, the term "phone" is generally used for any sort of contact that's made via voice into a microphone, as opposed to CW (Morse Code), digital, RTTY etc.