You can travel in time just walking from the center to the Khan el Khalili souk. You'll enjoy seeing the modern Cairo turning to old. Of large buildings to the streets organized by unions. Is a good option to enter and know the big stomach of this dinosaur city.
Taxis are so cheap for tourist in Cairo.
You can rent a taxi for a whole day or even for some days.
Try to get a taxi driver that speaks english, if you are lucky he would talk you a lot about the city and the people who leaves there.
Don't expect a nice taxi! Minimum 15 years old car :)
Nowadays the subway is convenient, cheap and fast. There are wagons for women and men separately. A good way to avoid traffic. You will find the metro all arround the city.
Whoa. Cairo is a whole other planet. Crossing the street is practically suicidal. As a woman, it takes some adjusting to, as Arab customs are in high gear. But after a couple of days, all begins to settle and what I found was that there is a beautiful rhythm to all the chaos that fills the days and nights of Cairo. Saw the pyramids of course--anticlimactic! Ate some egyptian goodies... and marveled at the notorious Nile.