When I migrated from my Palm Centro (best smartphone ever) to my current BlackBerry, I did the following: 1) Export Palm contacts from the Palm Desktop software to CSV (comma separated values or tab-delimited text) format. 2) Import the CSV file to your Google Contacts account. 3) Wirelessly sync Google Contacts to your new phone using the free Google Sync app (link below). 4) Verify data was transferred appropriately.
Google Sync details: http://www.google.com/mobile/sync/
You should be able to follow the same process for your Palm Calendar by exporting your Palm Calendar from the Palm Desktop software to a file (save the exported file to your desktop, or an easy to find location on your computer), then import the Calendar file into a NEW Google Calendar, not your primary calendar (in case there's conflicts or problems, you can delete the secondary Google calendar without losing your primary Google calendar items). Google Sync should allow you to choose more than one Google Calendar to sync with your new phone.

Palm did not provide you an option for that function for treo's or centro's. You can export them from the palm desktop as vcards or comma seperated values (.csv) files and import them into a program such as outlook which would then enable you to syncronize with other smart phones like blackberry's windowsmobile, Android, or iphone.