Option to combine multiple orders into one Pick List

It would be handy to be able to combine multiple orders into one pick list, perhaps with checkboxes beside each order item and an additional "export combined pick list" up top?

For example, we have a client who we hold their orders for one monthly shipment. Having the capability to combine all of their open orders for that month into one sorted pick list would be ideal (the sorted pick list has been entered as a separate idea).