RE: Which diaper bags to take to Palm Springs??
Too many carry on bags! Really, with all you'll be juggling (stroller, car seat, toddler), I'd stick with one or maybe two carry-ons max. Cut back your carry on stuff to the bare necessities (usually revolving around your DD, and anything that can't be checked like medications or a laptop).
The Skip Hop sounds like a good choice once you get there, although perhaps take the Dash because it gives you more flexibility should you be gone from the hotel, say, all day.
Single mom to
DS ("twice exceptional") - September 2002
DS - February 2006
DD - July 2009
DD - July 2009