Thanks for the replies. You wont believe this but as incredible as it sounds this froglet, with a large section of guts hanging out, has almost completely healed! The guts hung out about 1/8 - 1/4 of an inch between its front and back leg on its right side. The skin from his eye to its back leg on the affected side was black and the froglets itself was very very thin. The weather had gotten very cold, dipping down under freezing at night, and there were few bugs to eat. S/he was having difficultly hopping and guarded that side by keeping both it's front and back legs tucked into it's body, which is why I took it in, hoping the better conditions and food availibility would give it a better chance to heal. Thankfully my plan paid off. I just left the lil guy alone and noticed the section of gut was getting smaller everyday and the skin, which was turning green, was healing around it. S/he is hopping around and doesn't guard that side any longer. S/he has more than doubled in size and is looking very healthy. Ill keep her/him inside for a few more days and then let him/her go while it's still warm out. Before I let her/him go ill get a pic to post, it's truely amazing what these Gray Tree frogs/froglets are able to over come.
Lucky, the 3 legged froglet, is still small, but looking healthier. S/he is still fairly clumbsy when hunting, but s/he'll have a permanent home with me.