Mobile gps phone
either the [ipaq hw6950], since it's available locally and will support Java easily,
or the loox t830 - http://www.solopalmari.com/content/view/1741/143/1/2/ , http://www.fujitsu-siemens.com/campaigns/pocket_loox_t/index.html - since it has usb host mode and an autofocus 2mpix camera and slays the hw6950 in just about every other way
http://support.fujitsu-siemens.de/forum/viewforum.php?f=25 - fujitsu-siemens evidently ineffective support forums
http://www.expansys.ca/forumthread.asp?code=130765&thread=5 - let's see if expansys can help
data access
Of course, I must be a fool for wanting such a device, since in Canada, after Fido pulled their $50/month unlimited data plan, data access on GPS is stupidly expensive (something like $20 to send a high resolution image).
development
http://dcg.ethz.ch/theses/ws0405/gps_ipaq_report.pdf - nice doc on creating GPS apps using Jeode
using swt with ibm's j9 - http://forum.java.sun.com/thread.jspa?threadID=604997&tstart=0