D.R.
hi L.. i dont know anything about the gps things, but i will be checking back here to see. i bought one that stunk, i dont remember the name. the kids mostly wanted to see if they could make it go off. i did want to give you some advice... what i did to stop the wandering off was to bring them out in the stroller. then when you are in a safe but tempting place (the mall or the park on a fairly empty morning works well) let them walk. if they walked away from me, they were strapped back in. immediately and mercilessly, no second warnings, no second chances. and there they stay. you have enough time before your trip to give this a shot, it worked for me. also, i put id on my kids, they have a bracelet called id inside, with my cell number etc inside it. id_inside.com, i think. (never put their name outside). and the bright clothing thing is great too. but there is no substitute for you, you have to teach him to stick with you. try the stroller thing, it works even better if you are someplace fun (NOT disney, lol) to teach him. and if he doesnt learn, then i would absolutely leash him or stroller him, whether he liked it or not. no way i would take a chance, especially not at disney. you will have the stroller for the baby anyway, right? so, if you dont want to do a double stroller, then bring a sling or baby bjorn or whatever along and you can take out the baby and put him in if you need to. (dont forget about the carseat if you are still using it in the stroller, that wont work, use the stroller without the carseat while you are "training" him). though you really should use a double, imo, because he will get tired and hot and whiny and he should be able to take a break. btw, my daughter absolutely lost her mind the first couple of times i did this, she fought. i crossed the straps of the stroller across her chest and let her scream. she sticks with me now. sounds harsh, i know, but some things cannot be done halfway. kids do vanish, you know?? they are slippery little suckers, dont mess around. and have a good trip :)