Beware the schoolchildren! They will come up to you everywhere asking you questions until you have quite lost your patience. You might even find yourself a tourist attraction when they take pictures of you! This happened quite a lot at the tourist sites like the pyramids and the mosques. This group of children were at the Egyptian Museum and eventually had to be chased away by the guards.
When crossing one of Cairo's big streets, don't get scared. It's quite easy if you follow a simple rule:
NEVER RUN OR HURRY!
Never try to pass quickly just before a car! they will take care and even don't pass in front of you but in your backside.
Move on slowly from lane to lane - it's not important whether you can see them or not!
Look out for hand signs Egyptian use in traffic. They are very very helpful even when you drive by your own.
And believe me - it looks much worse than it is.
When I was in Cairo for some months together and then came back to a 10000 inhabitants city in Germany I was almost run over by a car that didn't hoot or move aside! In Cairo never.
Try avoiding crossing the main streets because pedestrians crossing does not exits in the Egyptian vocabulary. Cars will never stop for you so be very careful.
Watch out for the Cairo traffic. The speed limit is roughly 90KPH but nobody inforses nor follows that. Speeding cars are common and do not stop, so be extremely careful!