PicoForms, the company I work for, has released a new website which contains a complete make over of the design but more importantly demos of the products we have. There is a great demo of the MIDP implementation (at PicoForms we call this the Micro Edition Browser) which uses several back-end WebServices to retrieve data directly from the forms using SOAP. There is also a WebStart demo of the Personal Edition Browser, which currently only have one demo form but a good one since it is the Tax Form from the Mozilla XForms Project.
Check it all out on http://picoforms.com.