Apache SOLR calls for a quirky JSON format when you want to add multiple entries at once. ( http://wiki.apache.org/solr/UpdateJSON#Update_Commands -- notice the 'add' nodes)
In a nutshell, I need to be able to create JSON that looks like this:
{
"key": "val 1",
"key": "val 2"
}
In PHP, you can easily create an array, but this JSON structure calls for an object with two keys of identical name that are explicitly not in an array.