If you have no plastic card (either a debit, or a credit one) and do not wish to be bothered with travelers cheques (where commission charges tend to be quite high) you will be better off taking with you determinate currency.
At present, these currencies are clearly Euros (#1, offering the best exchange rate) and US Dollars (as widely accepted but somewhat marked down by the Exchange Bureaus & banks due to the recent slide).
Some other currencies are accepted, but they are heavily marked down.
Wahat Road, Giza, Egypt
Good for: Couples
Bahariya Oasis, Bawiti, 11341, Egypt
Good for: Solo
198 Pyramids Road, Taa'won Square, Giza, Egypt
Good for: Business