This is an active team building game and requires participants to move about a lot and so can be also used as an energiser.
Tie 2 ropes from one tree to the other to form a rectangle. Connect string between the top and bottom to form holes, the holes can be a varity of shapes. Ensure when making the holes that there are enough holes for each person in the group and think of the age and size of the group members(weight and height). The point of this activity is to get all members of the group through the holes in the web.
Only one person per hole and no one can go over or under the web. Members have to work together to figure out the order people should go through the holes. If anyone touches the strings or knocks the web while passing through the holes the whole team has to go back and start over again. If you have a large group you can set up two or more webs, break the group down into smaller groups and have groups race to see who can finish first.
When they are lifting someone, remind them to protect the participant's neck and shoulders. Stop action if they are doing anything that you deem dangerous. If the web breaks you may stop the activity and make repairs or start the review.
The problem brings up all the standard group/team problem solving issues, quality issues, (what is a web touch?), ethical issues (calling a touch when you see one), and strategic issues (when do we cut our losses).
You can turn this whole activity on it's side, and use two folding tables as your sides... and string the rope/string between the tables to make a sideways spiderweb... the objective then is to get people through from top to bottom instead of from one side to the other.