Ok, thanks.
I might just run it as a separate application (which has a UI button) like compass which I don't use.

That would be easier, and allows you to use the screensaver function for something else...

Wish there was a large speedo inside primo like igo 8.3 had with the neat dashboard/trip monitor screen.
Is it possible to put that screen into primo somehow?

That was a skin feature, Dimka doesn't have this feature, I'm not sure about others.

Editing skins is not for the faint hearted.

Here's a point for you...

Garmin Mobile XT has exactly what you want. Speedo, Trip mileage, everything in like a little side app on it.

Yes I have Garmin on my Asus Padfone and I like Garmin and would use it on wince devices but the graphical interface is not good compared to the padfone, whereas Primo is good.

Ok so speedo.exe work great with largest font on the 800x480 screen. (thanks)
I run it from the application button 'compass' (which I don't use anyway)
One issue is with speedo.exe on screen and you want to say change radio stations you need to touch screen and push 'exit' on speedo.exe otherwise when you try to start it again the GPS port will be in use and then a reboot is required. I presume if you don't exit properly and start the app again a new instance of speedo.exe starts?
Is there a way to exit speedo.exe just by touching the screen instead of pushing the exit button?

If your device has programmable hardware buttons then a simple script attached to the button can start it, or kill it if it's running, if not you can either use a floating button, that when tapped kills it, lastly you could create a script that kills it when it has lost focus, this may not work though.

Thanks. The floating exit button sounds good. How would I add that?

http://www.navitotal.com/showthread.php?9920-HYSCv2-(Hide-Your-Speed-Cams-V2)-for-all-(WinCE)-versions-of-iGO

Here us an example of a floating button I used for another project...

What you would need to do is create a script that starts the button then starts Speedo.exe, you call this script to start the Speedo.

The button, when tapped starts another script that closes (or kills) Speedo.exe and the button.

I'm not near a computer to try this out, but it should be possible to auto close the Speedo when it has lost focus by using mortscript.

Thanks. Bit beyond my expertise.

Read here about creating scripts, it's not that hard.

Thanks, I'll give it a go.