Over the weekend I found that Google has a version of Maps specific to the PalmOS. I already had the generic version for cell phone, which also works with my Palm T|X. But on the weekend, I noticed that there was an extra item on the page: "Download Google maps for PalmOS 5 device (US/Canada)".
I clicked it, and found Google asking permission to download a PRC file (that's an .exe file for PalmOS). Once downloaded, I ran it as a separate PalmOS Program.
It provides PC-like access to Maps, including directions, pushpins, details of found locations, and satellite images. Missing is overlaying roads onto satellite images. Also missing is support for rectangular 480x320 displays, like the T|X; the maps are limited to the square 320x320 size.
For it to operate, it requires WiFi access; maps are not cached, so I can't store San Francisco before my business trip, and then zoom and pan about once there. I can do that only if I find a free WiFi point in the city.