A question came in to the MOSS Help and How To forum about creating a form that allowed multiple approvers to be specified at the time the form is being filled out.
I went ahead and created a form in InfoPath and a simple workflow in SharePoint Designer to allow the selection of the approvers and assign tasks for the approvers. It is a simple form and workflow both. For production you would want a more robust solution. If you have ideas for a better solution, please let me know in the comments.
Instead of writing out all of the steps I created this short video to demonstrate how the form, workflow, and SharePoint library work.