I read your post in the frog forum and your the type of person that gives the turtle and frog hobbyists a bad name. The sterotype is that people get these "disposable" pets and then when the fun wears out, throws them away and in your case let's them go. I would like to bring up a little situation here. A few years ago exotic bees, that someone had been keeping, had gotton loose and mated with the local bees. They produced a somewhat super-bee know as killer bees. These bees that shouldn't even be anywhere near the southern areas of america and mexico are now attacking and killing people and pets. This is just ONE example of how letting none-native animals go can devestate a population of wildlife and people. The chance that your frogs have of making a impact on the population where you let them go may be very low, but its the part of the responsibility as a pet owner to know and not do these things.
~And in response to your turtle question why would you want more turtles if your abroad and probably gonna move again? Take responsibility and be a good pet owner. No pet is disposable.