Can you give me an example of two streams that would have a merge sort needed that would be impossible? (I'm still relatively new to XML processing, but it would seem that merge-sorting would be very simple with N streams using callbacks, at least theoretically...)

------
We are the carpenters and bricklayers of the Information Age.

Don't go borrowing trouble. For programmers, this means Worry only about what you need to implement.

Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified.