If I have the map open, but not routing anywhere, two buttons are displayed at the top of the nav screen. Both have a house on them, arrows pointing in opposite directions, and matching numbers that seem to increment /decrement as I drive.

I looked through the manual and there isn't a mention of what they are or whether I can turn them off.

Does anyone have any insights?

I believe they're the house or business numbers you'd see as you drive down the road - although they're not at all accurate the couple times I've used the nav screen.

Is it possible to turn them off?

i always thought it was the amount of POI and in which direction they where...lol

House numbers on either side of your vehicle as you travel down a road. Apparently my house is not 7*** it's 4***. Just slightly off....

Can they be turned off? They just take of space....

I believe it can be disabled by selecting the disable animation from the navigation settings menu.  Regarding the benefits of seeing the odds and evens on the map, I can see this being helpful when trying to locate a retail business in a commericial area where you know the address you are looking for but do not have it programmed in as a destination in the navigation system.  Since addresses ending in an odd number are on one side of the street and even on the other, simply knowing which side of the road the odds and evens are on via a glance at the screen is a nice feature in my opinion.  I've only had my AVIC for 24-hours but I can recall many times when I was trying to locate a business in shopping business strips but not knowing which side of the street it would be on.  Many retail locations do not display a number on their business so this will help at least knowing which side of the street the odds and evens are on.