Hi Tom,


Given those choices, no question - the 24-105mm f/4L IS.


I'm facing a similar but less restrictive choice soon, myself - a trip to Storyland in New Hampshire (theme park for toddlers, primarily) andand some other nearby locations. I definitely want to take more than one lens, so I'm looking at a Lowepro Primus AW for the trip (I have a Flipside 400AW which is about the same size, but holds only camera gear - the Primus is a two-compartment backpack, so I can carry other items like snacks, raincoats, etc.). I should be able to fit my gripped 7D, 17-55mm (I want wider than 24mm for my general purpose lens), 10-22mm for scenic mountain shots, and either the 70-200mm f/2.8 II or the 100-400mm, not sure which yet.


But for a one-lens trip, the 24-105mm is ideal - that's a lens I usually take on day-trips with my 2.5 year old daughter (sometimes the only one).


Have a great trip!


--John