[greggsy]

Interesting. In Australia, people often use erhm or aah/aahm as an interjection to announce that they are about to commence speaking.

[redwall_hp]

Japan has that too: あの (ano) and えっと (etto) are used as fillers to indicate that you're about to say something.

Moshimoshi is fully a contextual greeting. (You'd use the good morning, good day, good evening equivalents in person.)