I committed some code for populating pre-generated PDFs with fields. If you want to try it out,
check out the trunk and compile the PDF-module and make a xhtml-page lik
<p:form xmlns:p="http://jboss.com/products/seam/pdf" URL="http://localhost/Concept/form.pdf"> <p:field name="person.name" value="Me, myself and I"/> </p:form>
(of course EL-expressions are more useful)
Grab the sample form here,
stick it in the webapp and point the URL on it.
What features would be useful you in this context?