One of the most important drawbacks of my Nexus One is the limited choice of applications if you are outside US and couple other countries. Android Market sells for couple countries only, and native free Turn by turn navigation application is available in USA only. That is a shame, as I need navigation in my country as well sometimes.
There are some paid alternatives. For example, CoPilot by ALK Technologies is quite good and reasonable application for android. The single drawback is that it is not available in my country.
However, recently I found a free solution for this problem. The application is called Nav Launcher . Apparently, Google maps do not work in Canada as well, so some people there created a version that uses modified google maps. It works worldwide. It does 2 things. First, it creates a nice launcher for custom google maps in navigation mode. Second, it allows choosing which maps to launch : native or modified. Native maps provide navigation in USA only.
To enable installation of Non-USA navigation, you will have to enable installing from third-party sources. To do so, go into settings->Applications and mark Unknown sources checkbox. This will allow nav launcher to download and install Brute Maps, which are based on Google Maps 4.0.
There is another small issue. I am still running Google Maps 3.4 on my Nexus one, as maps 4.1 is available in USA only (maybe in some other countries). This is quite depressing, as I see no reason for Google to limit availability of free applications that should be the same worldwide. I am quite sure that I would be able to install it through VPN if I really wanted that. Though question remains… why such artificial limitation?
Overall, I am unhappy that Google does not want dollars from many world countries though their app store. This limits developers as well, because there is a huge market for local apps outside USA and UK as well. These applications will have different specific country-related needs.