MAPOPOLIS!
I haven't tried it with the new rom yet (going to flash soon), but I've been using this on my Pocket PC with my Bluetooth GPS puck on my dashboard for the last 4 years, and I can honestly say its the most under-rated peice of software out there.
Its nothing to look at, its actually rather boring graphically (no fancy 3D views or anything here), however what it DOES do, it does
EXTREMELY WELL.
That is, it gives clear, concise, turn by turn spoken directions with a text-to-speech function to read you the street names (something this did long before standalone GPS units offered it). Its got dynamic zoom stuff so you can see the details of the upcoming turn when you need it, and then go back to the big picture when you're on the highway, and after trying other applications (tom tom, gmaps, etc), I found that no other application was as good at in-car navigation.
Its not the best as far as user-interface (finding a location to route takes some getting used to), and visually some of the others look cooler, but I find that once you've got your location and destination, its one of the best at making sure you stay on the route and get there.
EDIT: I forgot to mention that Mapopolis stopped selling their software this past year. However, the application (which is free) is still available for download if you go straight to their download page (the main page at mapopolis.com no longer has links to the software). A google search will give you this:
http://www.mapopolis.com/downloadppc...44.52999078068
The maps (which are the parts that cost money) are still available to download if you have an account with them from before they stopped selling them, however demo maps are still available for free to the public (link can be found on the page listed above), and work for 7 days. After that, unfortunately, the only option is to hack them to work since they are no longer selling the full version (very easy to crack- maps have a single bit to determine demo status. If you change that bit to 0 in a hex editor, the map becomes non-demo/full version. Look it up for further instructions).
I actually find it very sad that they are no longer selling the software, since I haven't found any other good ones that speak street names. Let me know if I'm overlooking one, please!