Getting to downtown Cairo can be a pain. LE 40 is a good price by taxi, although it can be quite difficult to negotiate this price if you are not an Arabic speaker. Refuse to pay the "ticket" (airport parking fee) for the driver.
For the adventurous, catch a public bus to Midan Tahrir or Midan Ramses. Walk 5 minutes out of the terminal to the big undercover bus station, and ask a local, but don't catch the notorious (non-aircon) green buses. Rides are just under LE 2. It takes around 1 - 1.5 hours to reach downtown. Finally, there are also direct express buses to Alexandria every 30-60 minutes. Cairo International Airport is well served by EgyptAir, the national carrier, and others such as British Airways, Air France, KLM, Singapore Airlines and Lufthansa.