I got the Haicom MMF GPS and it's working fine. I am using zGPS, but as Gaines said, not really impressive. My problem is I didn't find good maps. Since I am not in the USA, I cannot use the maps pointed to by zRoadmap and others.
I found very good maps, but unusable since encrypted and used to be used in conjunction with the editor's software running only on Windows or Windows CE.
Is there any resources on the web to learn maps formats and howto produce them?