As I found with a quick Google search:
IBM Java implementation, WebSphere Everyplace Micro Environment is available at no cost to customers who purchased a Treo 650 smartphone, a Tungsten T5 handheld or a Zire 72 handheld. Other customers with supported devices can purchase IBM WebSphere Everyplace Micro Environment at Software Connection for $5.99.
Go to http://www.palm.com/us/support/jvm/ , fill in the form, select your device and download WEME571.zip and follow the installation instructions (they are fairly simple).
The above is from http://gmapsontreo.blogspot.com/
I think that answers the question for you.