Re: How to pt when not at home
We used pull-up diapers when we went out, just in case, but went potty right before leaving the house. Anytime a grown-up went potty at the store/restaurant my DS/DD got the chance to go also. Also used the Potette you mentioned and we loved it. Fit right into my giant mommy bag. Actually I should offer it on the FSOT...hmmm.
Anyway I agree with Nerissa about not stressing and not pushing the child until they are ready. There's nothing going to ruin a dinner out or an outing like having to stop and clean up a messy wet child AND carseat/restaurant booth/airplane seat(!)