Even though the HTC Touch only comes with a rather slow processor, it is still powerful enough to run a fancy vehicle navigation system. After reading through lots of reviews and forums on the internet I decided to give TomTom Navigator a chance.

The current version 6 runs smoothly on Windows Mobile 6 and is reacting very quickly to user's actions. Even calculating the most difficult routes is a breeze so no worries on that side either. What I like most about the software is its quick user interface which seems to be made especially to match the HTC Touch's gesture philosophy. Even though it doesn't come with real TouchFlo™ support, it allows you to access all menus and options using a thumb thanks to the big screen buttons as you can see in the following picture. Apart from that you can configure TomTom Navigator 6 to your own preferences, from day/night view, 2D/3D maps to the amount of detail that is being shown on the navigation map.

What's also very convenient is the ability to browse the map even if you haven't got any GPS receivers at hand. So you can use the TomTom Navigator as a small but powerful city map if you're on the way in a foreign place for example. Browsing the map even works at very zoomed out levels.

The maps don't take up that much space either so if you've chosen to go for a big enough MicroSD Card you're on the safe side.
In order for your HTC Touch to work as a car navigation system at its max, you will need to buy a GPS receiver - it doesn't come with one which isn't surprising owing to its small form factor.
So after checking out a couple of Bluetooth GPS receivers I finally ended up with the RoyalTek RBT-2210, a wireless device that I can only highly recommend in conjunction with the HTC Touch. It's quick, it keeps satellite connections easily and comes with a great battery allowing you to use it without external power for more than 23 hours.

Unfortunately it doesn't seem to be in stock any longer so you might as well check out its successor, the Royaltek RBT-2300. It also features the SiRF Star III GPS chipset, can connect up to 20 channels in parallel, can operate for more than 9 hours and thanks to its data logger function can record travel information into the internal memory. As its predecessor, it's thereby extremely small and light-weight, you can even use it for hiking trips or bike tours.
Finally, add a Universal PDA Mount to this combination of devices and you have a full-featured car navigation system that also allows you to make phone calls and can be updated easily. And you can reduce the amount of devices you have in your household.
After you've bought all ingredients you can start setting up your new navigation system. Just follow these few easy steps in order to start navigating:
That's it! Enjoy your ride and drive safely.