JOHANNESBURG (Reuters) - Muammar Gaddafi was once crowned Africa's "King of Kings" by minions from south of the Sahara and the turmoil in Libya can only increase the chance of north Africa's revolts flinging sparks across the desert.
There has been little echo of the Arab uprisings so far.
The dynamics are different in sub-Saharan Africa with ethnic division, less urbanised populations and poorer communications making it harder to organise mass movements in some states while unprecedented growth prospects reduce the impetus elsewhere.
But some long-in-the-tooth leaders are clearly worried.
In Zimbabwe, 46 people were arrested on charges of plotting protests against President Robert Mugabe similar to those that toppled the rulers of Egypt and Tunisia: They were caught watching pictures of the revolts to see what they could learn.
In Uganda, as voters gave President Yoweri Museveni a fourth election landslide despite opposition cries of foul, phone companies were ordered to intercept text messages with words such as "Egypt" or "people power".
"There is a common denominator in that there is a lack of democracy and lack of opportunity and that applies to much of Africa," said Greg Mills of the Brenthurst Foundation thinktank.
"I am sure there are in a sense those who would take heart, but African leadership continues to play a very canny game in dividing and ruling," he said from Cairo.
Gaddafi has tied himself strongly to the rest of Africa, championing its unity and bankrolling compliant leaders.
The lesson from Libya for Africans challenging autocratic systems could be Gaddafi's failure to prevent the uprising - whether it succeeds or not - even with a bloody intervention.
"If people see someone like Gaddafi can be removed, it can have a huge impact on the way African civil society thinks about itself and the way it can put pressure on," said Petrus de Kock of the South African Institute of International Affairs.
"It shows you do not have to accept someone for 30 years."
Potential trouble spots in sub-Saharan Africa are those with most parallels in the north: those with seemingly unchangeable autocrats or dynasties and anger at a lack of opportunities.
Zimbabwe is certainly on the map although many pundits believe Zimbabweans are too cowed by forces who have loyally kept Mugabe in power for over 30 years.
In Cameroon, where President Paul Biya has ruled for 25 years, his opponents have called for a "Day of Rage" on Wednesday to demand that he not stand for re-election.
"Mr. Biya should draw the lessons from the humiliation of Mr Mubarak's departure," said opposition MP Jean-Michel Nintcheu. "Cameroonians live in worse conditions than Egyptians."
In Senegal, a man died this week after setting himself on fire at the gates of the presidential palace, copying the self-immolation which triggered the Tunisian revolt.
Frustration is growing in Senegal over power cuts and lack of jobs while opponents accuse elected octogenarian President Abdoulaye Wade of trying to engineer his son's succession.
In Gabon, the opposition draws parallels between the north and its own ruling dynasty since President Ali Bongo Odimba was elected in 2009 to follow a father who ruled for more than 40 years. Police clashed with thousands of protesters last month.
The yields on African eurobonds rose in late January over uncertainty in Egypt, but while Ghana's has since slipped back, those of Senegal and Gabon have not.
In central Africa, Democratic Republic of Congo could be a flashpoint as President Joseph Kabila plans his re-election.
On the eastern side, protests have hit Djibouti. Reclusive neighbour Eritrea could ultimately be at risk.
But different forces are at play in sub-Saharan Africa.
Leaders can exploit ethnic and sectarian divisions and are adept at the use of patronage to neutralise foes.
Whatever the rights or wrongs of Ivory Coast's post election crisis, ethnic polarisation makes a united popular movement difficult. Security forces will always be reluctant to switch to someone they see as a traditional enemy.
Organising mass protests is harder in rural Africa than in the more urbanised north, although cities are expanding and mobile phones and Internet access are spreading dramatically.
Apathy may also be a factor. A wave of post-Cold War protests brought a few meaningful multiparty elections, but left plenty of strongmen in power to hold only nominal ballots.
In countries which are more open than those in the north, greater optimism could prevent crisis.
A decade of unprecedented economic expansion has raised hopes for further improvement. Growth in sub-Saharan Africa is forecast at well over five percent again this year, slightly higher than for the Middle East and North Africa.
"If people are still suffering from oppressive government, poverty, frustrated ambitions, I think the general trend is a positive one whereas in north Africa there was a sense of stagnation," said Tom Cargill of London's Chatham House.
"For all the problems with freedom of speech, you do see a more outspoken and freer media which allows a release from the tensions. In a funny way, it shows how much sub-Saharan Africa has changed in the past decade and overtaken north Africa."
Additional reporting by Tansa Musa in Yaounde; Editing by Giles Elgood