InfoPath Dev

I have 30 subsites (one for each customer) in Sharepoint, they all have the same forms and work pretty much the same. One of my forms is a Customer Service Record which is just basically a way for techs to record work done at a customers site. What I would like to do is add a "Travel" checkbox to this form and publish the new form to all the sites. Each customer is a certain distance, in miles, from the office. How would I do this: tech creates new CSR in a customers SP site and had to drive there so he would put a check in the "travel" checkbox, then behind the scenes once form is submitted the round trip mileage would be automatically entered into another form with date, customer name and mileage amount so that once a month he can submit it for reimbursment. The tricky thing is that each customer is going to be different mileage. I am sure I am going to have to change the form 30 times and publish it as each CSR form will have different mileage info.

Any help/Ideas?

One suggestion is to create a content type and then associate the InfoPath form as a template for that content type.  Then in each of your sub sites, in the form library, use the content type.  Then when you update the InfoPath form, just update the template that is associated to the content type and it will be pushed to form libraries using that content type.

Make sense?

That part does, however, I still have a question. I have a web enabled form called "CSR" and evertime I go to a customers site to do work I fill out a CSR on the proper site that is tied to that customer. When I click submit it creates a document under the CSR Page. What I want to do is add a "Travel" tick box and define that box as the milage for that particular customer. I would like that milage info sent to another form, database or something so at the end of the month I automaticly have a milage expense report. Am I making sense? It makes sense in my head but I am new at this and dont know exactly how to do what I want.