Yes there is a second group, they are from the tail section of the plane that broke off mid flight, it landed on the other side of the island, there was originally 23 survivors but there is only 5 or so left. They were found by Michael, Jun and Sawyer, when the others came and took Walt, the raft was blown to sh*te and they drifted back to the island but around the other side, where the tail section guys captured them. Walt is still missing but that hot blonde chick (not the preggers one, the other one) keeps having visions of him. Walt keeps speeking jibberish to her which if you play it backwards is actually phrases but I cant be arsed doing it, I think they are linked telepathically somehow and walt is also the reason the polar bear rocked up in series 1, go to yahoo7 for all the secret bits about that. The hatch got opened and inside was a guy named desmond who has been there for years pressing a code into a computer every 108 minutes, he nicked off and now lock and jack are doing the code, they were shown a video saying that if the code is not entered in, the worls will basically end, they both think it might be a load of rubbish and its all just an experiment to see if someone will stay down there and do it, but they both dont want to find out either. Tonights episode, had the tail section guys, along with Michael, Jun and Sawyer treck off to join up with the other group, but Michael pissed off when he got a tip on which direction the "Others" were in, hence the direction he could find his son, but he was tracked back down by Jun and some other dude and convinced to go back as walt was wanted for a reason therefore is probably still alive. You also got a look at the "Others" and they appear to me at least to be young peopel, if not children, they are all barefooted some are dark skinned and one was carrying a teddy bear with a noose around its neck. Dazza.