Offline XMl Forms

We have just completed design of a enterprise wrokflow system to handle workflow within our orginization from Sales to Billing. Sales reps fill in online forms (xml) in the central sales center. We are now faced with the task of how to port those xml forms to an offline format for use with our field reps who sell on the road.

Are there any solutions out there tht allow users to fill XML forms out offline and then submit them later on.