I don't know how Erik installed it on his 7610 but since my 7610 wasn't supported I downloaded the 6600 version and held my breath. Luckily (since there are so many differences between Java on mobile phones it's luck whether a given Java midlet works on a given phone), it worked!
I installed the application to my Nokia 7610 today to try it out. Overall, the interactivity is nice. Map movements are fluid, and navigating the application is pretty straight forward. However, there certainly are some compromises. To start, the application pops up a networking confirmation dialog for every network request. That means you spend a lot of time repeatedly clicking "Yes" while trying to scroll or zoom your maps: