I haven't seen the tv show lost since the 2nd episode of season 2. What's happened since?

too much, just to much to write!

In short (spoilers!):

The Losties must enter 'the numbers' into Desmond's computer in the hatch every 108 minutes. The people who abducted Walt is one of 'The Others', a group of people living on the island. The Losties capture a man called 'Henry' and interrogate him. He turns out to be called Ben, leader of The Others. The survivors of the end section of the plane meet up with the main survivors. Shannon is killed. Michael is captured by the Others and is allowed to speak to Walt. Jack, Kate and Sawyer are kidnapped by the Others and imprisoned. Michael and Walt leave the island on a boat. Desmond's girlfriend, Penny, is looking for him. An electromagnetic pulse goes off on the island, making the island visible to outside radars for just a second.

Ben requires spinal surgery and asks Jack, a prisoner, to do it. Jin and Sun kill one of the Others. Kate and Sawyer escape. Juliet, one of the Others, defects and joins the Losties. Desmond has flashes of the future and foresees Charlie's death. A woman parachutes onto the island, claiming to be a rescuer from a nearby boat. Charlie swims to an undergrounf Dharma station and speaks to Desmond's girlfriend on a video phone, but he drowns.

The show uses flash-forwards to reveal that at least 6 people make it off the island, including Jack, Kate, Hurley and Sayid. Other people from the nearby ship arrive by helicopter. They claim to be rescuers but are actually after Ben. Sayid and Desmond take the helicopter back to the ship.

That's about it so far.

Much, so much things that already been done...I recommend you to watch it the whole Season 2 to 3!! rather than asking question about it!! It's hard to explain

They built a big mall and casino. And now Paris Hilton shows up all the time and ruins the whole vibe. The end.

oh....everyone died and they have a whole new group of characters