In addition to the typical meanings already noded above,
moshi moshi is also a way of saying "
hello" in another sense:
茂：明日、札幌へ行ってくる。
恵子：もしも～し！デートを約束したでしょっ・・・？
Shigeru: Ashita, Sapporo e itte kuru.
Keiko: Moshi moshi! Dêto o yakusoku shita desho...?
Shigeru: I'm going to Sapporo tomorrow.
Keiko: Hello?! You promised we'd go on a date!
Remember, boys,
don't piss Keiko off.