(First, much thanks to Mateo Geoly for posting these IPs on Facebook).
Apparently — although for how long this will last, I do not know — you can get around Egypt’s block of communications/social networking websites by using the numerical IP address as opposed to the name (which has to be resolved by a DNS). So:
To bypass government blocking of website names, use numerical IP addresses:
For Twitter “128.242.240.52”
For Facebook “69.63.189.34”
For Google “72.14.204.99”