It is amazing to this observer how certain acts of defiance become catalysts for dramatic change.
When a poor but highly educated vegetable trader in Tunisia had his vending cart overturned and destroyed and he subsequently self-immolated himself three weeks ago, his act became the spark that brought down the Tunisian ruler and his government (along with the Tunisian general of the army who refused the order to fire on Tunisian protestors) people in Algeria, Mauritania and particularly in Egypt have become emboldened with some following the lead of the Tunisian man and self-immolating themselves.
The act of self-immolation (as is occurring in some of these Arab countries) is one of absolute desperation as well as defiance against the established political order.
In the Arab world, all countries are controlled by autocrats whether they are presidents (elected in trumped up elections), emirs, kings or ruling families. Despite some of these countries wealth (mainly from oil) controlled by these elites, the people do not share in this largesse, are politically and economically oppressed and desperately poor (supposedly over 50% earning less than $3 per day in Egypt) and though increasingly more highly educated (as the man in Tunisia) there remains extremely high unemployment (over 20%) and few opportunities to escape from their economic destitution.
Yet even in the Middle East communication is instantaneous with happenings broadcast from around the world. Now the recent events in Tunisia have seemingly captured the latent spirit of opposition protest in Egypt (that weeks ago were moribund) the largest Arab country of some 80 million people where opposition leaders are calling for "street level protests" next Tuesday coinciding with a public holiday.
Mohammad ElBaradei, an Egyptian and former U.N. chief nuclear inspector has warned of a "Tunisian style explosion in Egypt". 
Though muted in his call to actively support next week's planned demonstrations, ElBaradei said, "What has transpired in Tunisia is no surprise and should be instructive both for the political elite in Egypt and those in the west that back dictatorships. Suppression does not equal stability, and anybody who thinks that the existence of authoritarian regimes is the best way to maintain calm is deluding themselves." 
He repeated his call to the Egyptian government to "implement urgent political reforms"that without drastic improvements, a Tunisia-style explosion in Egypt would be unavoidable." 
We in the U.S. perhaps do not identify with the self-immolation in Tunisia, Algeria, Mauritania and Egypt particularly as an act of economic desperation and political defiance. We may collectively not experience the level of economic deprivation and political oppression suffered by the people living in these repressive regimes.
Be that as it may, the act of self-immolation in Tunisia has been a spark and lit a fuse that is being ignited in the Arab world. It brought down the leader in Tunisia; it remains to be seen what it will bring in Egypt and beyond.