When he was a bump he was "it" to start with and then when we knew he was a boy we made special effort to refer to him by name, even though he was still a bump. After he was born we kept referring to him as "Little Man" but Andy wasn't happy with this.
I found myself often calling him "Pickle" but Andy hated that one even more, especially as we both know other children who are often referred to as "Pickle". I tried calling him "Chutney" for a while but it didn't feel right. For a short time he had no nickname at all and was Simply Joseph, which was fine, but why should my child miss out on an important part of childhood like a nickname.
"Pumpkin" is a new one. I don't know why I called him that, but I did and it worked quite well because at lunch time I was feeding him mashed carrot and he sure ended up a nice bright shade of orange. I don't know if it will stick or if we'll end up calling him something else, but it will probably be something food related.
And I haven't even started the debate over whether it's a nickname or a "pet" name. Gaah!