Thanks for your answers. I found a backup with just the custom fields in it and restored that. Would still like to know of a way to dump just the data though

I suppose uninstalling/reinstalling the CRM module would delete your contacts, but also any custom changes you made in your views. If you didn't make new modules for your changes, this is not recomended.

Did you try to select all your customers in list view and delete them?

Now that I think about it... how about marking the customers as Invalid? You only need to set the Active field to False

Well the delete function is not a recommended one because of the moves dependent on either Customers\Suppliers\Accounts\ etc.

It's better to de-activate the customers and create new ones.

to do so, you can Use ODBC and MS Access to edit the table of res.partner, or do it one by one through openerp UI