Tether and Google Navigate at same time?

[Ed Witles]

Gang -

I got a Galaxy (wifi & 3g), but only plan to use the wifi part.

On trips, I am digging the Google Nav (and DI & Sky-FM).

Now, can I tether in the background and allow wifi for the Galaxy yet still have Google Maps and maybe the occasional phone call?

Just in case Angry Birds (all three) don't keep lil one amused.

Thanks!