one of these based on a thread posted on this forum. It seems to work okay as far as network printing goes but the email functionality is very buggy. Here's a thread from the eprint forum discussing the issue as I am not the only one having this problem.
http://h30434.www3.hp.com/t5/ePrint-Print-Apps-Mobile/ePrint-Not-Connected-error/td-p/310298
http://h30434.www3.hp.com/t5/ePrint-Print-Apps-Mobile/ePrint-Not-Connected-error/td-p/310298