I upgraded my Google Maps on my Nokia E71 after i read Kristupa's post on Twitter saying that he had upgraded his Google Maps to version 4.0. I googled and i was surprised to see the updated Google Maps have included Google Buzz, the latest product from Google. I downloaded a 1,6 MB Google Maps 4.0 and in no time, it has been installed on my E71. It works just like the old one, but with some addition on it's features.
If you want to download the latest Google Maps on your phone, just launch a browser on your phone and point to http://m.google.com.
Here's what it's like in a phone (i'm not sure what the phone is):