Ah… so it’s “Shalom” in the “who the fuck are you and how did you get my cellphone number?” sense. That, I’m OK with.
In Sweden, it’s pretty much the same as in Germany, except that some Swedes tend to answer with their phone number.
Isn’t that somewhat redundant?
Not necessarily. They might have dialed the wrong number but not realized it. Then when you get the litany “digit-digit-other digit” you start thinking “wait, isn’t it digit-other digit-digit” and realize their error.
Or something like that. 
In Finland we usually answer with our whole names “Firstname Lastname”, which allows the person on the other end know exactly which member of the family they’re speaking to (useful, especially if people tend to confuse your voice with that of your mother). However, now that virtually everyone has a cell phone, you get a lot more “hello”, “hi [caller]”, “WHAT?!” (my little brother) and other less formal greetings.
Norway is much like that. I had friends who’d answer the phone with the phone number when I was a kid (i.e. 80s), but I think that pretty much died out when we went from ‘area code + 6 digits’ to countrywide ‘8 digits’.
If it’s one of my friends calling I’ll usually answer something like “Hansens Grocery Store, you’re speaking with pope John Paul II”, or “Hi, you’ve reached… d*mn, I can’t think of anything good.”
In Thailand there are two ways. In a formal situation (a business, for example) they will answer the normal Thai word for hello/goodbye, “Sawatdee” followed by a Kha or Krup if the speaker is female or male respectively.
Most other conversations, especially on cell phones it’s, “Herro”. Embarrassingly, it still makes me laugh sometimes. I get wrong number calls all the time with people who don’t speak English at the other end. Now that I try and over-pronounce the L’s in hello, the confusion doesn’t last as long.
Well, this is not what happened. I’ve seen the claim that the word “hello” was invented by Edison before, and I can’t imagine where the idea came from. In variant spellings (hallo, halloa, hullo etc) it was a common greeting (expressing some surprise) for some time before the invention of the telephone in 1876, being used by Dickens in 1840 among other places. As a cry to attract attention its use goes back centuries. The most that could possibly be said for Edison is that he may have helped popularise that particular spelling, but “hallo” and “hullo” are both still in use in the UK to the present day.
The Cantonese shout either Wei or Wai. Just like either or either or potato or potato. Either’s just fine. But must be shouted.
For clarity’s sake, I think I ought to point out that my previous post was also in reply to Fear Itself‘s link, which I assumed that Crandolph was reffering to.
Similarly in Russian – the phone may be answered “Slushayu” (“I’m listening”).