Just read a horror story on Aussie DirtBikeWorld (http://www.dirtbikeworld.net/forum/showthread.php?t=20439) that happened where I ride near Brisbane, Australia - a guy got badly injured riding in a group for the first time (lifted out of the bush in a helicopter). No-one knew his full name, who to contact in an emergency, had to pack up his gear and drive his car etc.
2 things I suggest apart from tools are:
1) Put an ICE (In Case of Emergency) phone number in your mobile phone.
2) I have made a sticker for my helmet with my details - name, address, drivers license number and my wife's mobile phone number. If I'm found on a trail (or on the road) then people know who I am and who to contact.
One things about carrying tools is that you also need to know how to use them! I'm a novice mechanic as well as a novice rider