uhm...either I don't understand your question or you've been under a rock!
j/k But honestly let me know if I didn't understand your question correctly.
Mogul does have built-in GPS capabilities which are enabled by the new Sprint ROM released at the HTC site.
http://www.htc.com/us/FAQ_Detail.aspx?p_id=75&act=sd
The instructions on how to flash this ROM are stated on that page along with the download link.
Hope that helps.