Navigon is fantastic (and TomTom is decent,) but it's so much faster and easier to find points of interest in the default Maps app, or better yet speech-enabled "finder" apps like Siri or at least find-by-type apps like AroundMe (both are free in the App store.)
If you use AroundMe to find a destination (such as nearest ATM, or Chinese restaurant, or whatever) you can click the blue ">" on a destination pin and click "Show Route" to see an option to click "Maps" or "Navigon MobileNavigator." If you click "Navigon MobileNavigator" it opens Navigon with the POI you just selected as the destination, and your current position as the start point. Awesome, right?
If you get the JB app "Navigate from Maps" ($2 in Cydia) you can use the default "Maps" app (basically google) or Siri voice search to find the destination you want, then click "Map it" to see the map with a pin at your desired destination, then you can do the same as AroundMe and click "Navigate in Navigon (or TomTom).
That's how it's supposed to work. And apparently it works well for most people. It even works for me -- once. Then it seems hang on the "select a route path" until I uninstall and reinstall "Navigate by Maps" and/or Navigon and Siri and AroundMe. Huge hassle, of course. This is what it looks like after the first and only time it works after each reinstall:
Even after a reboot it hangs on the route select screen. Even if I just use maps and skip Siri (which really sucks, because Siri is awesome at using voice to search for POIs) It gives me the first voice direction, then clicking "start navigation" brings up the screen that usually shows 3 different routes, orange, blue, then green. The orange stays stuck at "0 ft 0:00 h" while the spinny-wait thing spins, and never stops. It hangs on that screen forever (I let it sit for a few hours once just to see.)
Same thing happens under 4.01 stock, 4.01 jailbroken, 4.1 stock, and 4.1 jailbroken (limera1n).
I
really want to do "find parking nearby" in Siri, click a close lot, then choose "Navigate in Navigon." And I paid $2 to do it, but it never works reliably. Anyone else have better luck with linking 'Navigate from maps' or 'AroundMe' to Navigon with or without "Navigate from Maps"?
edit: make sure the previous route is "cancelled" in Navigon and it'll work again. The guy who made "navigate from maps" answered me immediately and was a big help.