I hunt in a large hunting club (4000 acres and 30 members) with a sign in board. We have club rules that state that you do not leave anyone in the woods when you sign out... you are required to wait for the last man or woman to sign out before you leave. This is done to make sure that all people on the club are safe and do not need assistance.
With hectic schedules and the coming and going of everyday life, I find that I hunt by myself quite a bit, even though other members of the club are hunting at the same time.
Using a set of two-way radios, I leave one at the sign in board (with my name on a sticker on the radio) and take one with me. This way, I can let someone at the board know if I may be running late getting to the board to sign out, or if I need help.
This would prove highly beneficial if you were faced with dragging a deer out and needed help (I frequently hunt 500 or more yards from the dirt roads in the club), if the truck or 4 wheeler were to get stuck in the mud or if, God forbid, you were to get injured.
These radios have really come down in price and with great range, they are a great way to "stay in touch"!
Keep a pair charged up and share them with your buddies - they are a great way to stay connected.
Be safe and hunt smart!