One of them was telling people about the signs of the end of times. If you search for it in Wikipedia, you can find a long list. The signs of the end of times in Islam, most of which have come true.
He had LOTS of "Visions", all thanks to a brain disorder.
? Sword & Seizure: Muhammad's Epilepsy & creation of Islam
http://www.opednews.com/articles/opedne_abbas_sa_061213_sword_and_seizure_3amu.htm
During my childhood, I learned of the Prophet Muhammad's life in religious studies classes, and I was acquainted with some of his teachings. Later on during my undergraduate years, while working in Tehran's psychiatric hospitals, I had an eye-opening experience when I met a couple of schizophrenic patients who claimed to be the Messiah.
There are many prophecies to come true in Islam , all these prophecies are regarding the End of the World ( Last Day, The Day of judgement or in arabic youm-al-Qiyamah ) which is not known to mankind. We will know it is near as soon as the prophecies start to appear. This link might help:
http://www.inter-islam.org/faith/Majorsigns.html
The prophet had certain visions as mention in the Quran
http://www.islamreligion.com/articles/384/
There are also certain facts sent down through the Quran, which have been scientifically proven years after... for example: mountain roots, the appearence of a fetus in the womb when it is just a few weeks old ..and such stuff ....
http://miraclesofthequran.com/index.php
There are many prophecies 'yet' to fulfilled but what do you want to know? the 'minor' signs of the day of judgement or the major signs?
Prophecies Yet to fulfilled:
-Conquest of Rome by the Muslims - this will be done by muslims birth rates
-Conquest of Istanbul by Muslims
-Harj (so much murder and killings we will hear it every few minutes/hours.
-Natural Disasters
-Muslims will be divided into 73 sects, as were the christians 72 and the jews 71
-Chaos in the Middle east
-Israel will become the Superpower of the world
-Gold and Silver will be the currency of the time
-3 Sons of the King will fight (in saudi arabia) and there will be turmoil in the country, there you will see a man named Muhammad ibn Abdullah who will be the mahdi and will accept the leadership
-the ground will sink when the army from Syria come to attack the mahdi.
-Jesus son of mary will come back and fight the anti christ and say to the christians "i said worship allah, who is my lord and your lord"