I remember the following case (true story):
A student in a C 152 was sent on his first solo in spite of severe weather warnings. His first 2 circuits went fine, but on the third he couldn't get down! The squall line came quicker then anticipated by the instructor. The instructor ran to a nearby C 172 and radioed the student to just fly east... which he did. The instructor then bordered the C 172 and followed.
Neither had a chart or any other information with them!
I happened to be at a field located some 100 km east. We were just packing things in to go home because of the approaching weather system as we notice a C 152 suddenly appearing in the north. We tried to get radio contact but had no luck. Luckily this field is flat and very harmless (there's one in between that's like an aircraft carrier and restricted to pilots with at least 100 hrs.). We assumed he would land anyway, which he did quite successfully. We were surprised when suddenly a C 172 also landed.
Since they had no charts, they had no frequences and no idea where they were. We managed to find room for both aircraft in our hangars. They were picked up by friends who drove all the way out there to get them.
The next day, as we arranged the day before, I flew the C 152 and another pilot flew the C 172 back to their home base. The responsible instructor then flew us back home in the C 172.
So, no matter how short the distance or even if I'm planning to just stay in the pattern, I ALWAYS have my charts and other papers with me. You never know......
Westy