The speeches, made this month and last, have caused growing speculation that al-Qadhafi will use September 1, the anniversary of his coup in 1969, to announce a new direction for the country.
"The new phase which starts today requires that nothing be built by foreigners, and whatever is built in Libya will be by Libyans," al-Qadhafi said in one speech, according to the Libyan news agency.
But he also attacked Libyans - and by implication other Arab governments - for relying almost exclusively on their country's oil wealth, and urged them to invest abroad, innovate and create a more diverse economy.
"We don't produce anything," he said in a separate speech. "We sell only oil and consume everything. The kind of trade in which you produce nothing and import goods in exchange for oil - it's a catastrophe.
"The kind of trade in which you produce nothing and import goods in exchange for oil, it's a catastrophe"
"To explore for oil, to export it and earn money which you use to pay for imports, and to then sell those imports locally: This isn't prosperity. It doesn't lead to the nation's progress."
Closer relations with the West
Since trade embargos imposed against Libya after the Lockerbie airline bombing in 1988 were progressively lifted from 2003, the country has built closer relations with the West.
In recent months Libya has worked closely with the European Union over illegal immigration and with the US by offering close co-operation against Islamic militants.
Since then al-Qadhafi has increasingly held up Western economies and societies as role models that Libya should copy.
Most foreign observers consider Libya to be a military dictatorship
Libya could become an economic power like Japan were it not "socially backward" and reliant on foreign workers to do skilled jobs, he said.
"We take no significant credit for what's been achieved, because foreigners were the ones who did everything from the simplest to the biggest thing. Even to install a loudspeaker here, for instance, we used to bring a Korean or a Chinese to do it," he said.
Al-Qadhafi is renowned for his outspoken style and innovative ideas, but Libyans say it is unusual for such speeches to be made so frequently and to such a wide variety of audiences - from professional groups and state planners to teachers and religious students.
Al-Qadhafi's son steps up
Al-Qadhafi's outspokenness is also being matched by his son, Saif al-Islam, whose public statements had previously focused mainly on social policy and foreign affairs.
But in August Saif al-Islam told youth groups that Libya had no free press and that its political system should be more democratic.
Saif al-Islam al-Qadhafi (L) with the French president in 2004
"We say Libya is paradise on earth, it's heaven. What kind of paradise? We have no infrastructure. There are cities with no water," Islam told the meeting.
His father meanwhile has also criticised the country's stagnant and corrupt economic and political environment - both of which are founded on al-Qadhafi's own political 1975 manifesto, The Green Book, which is the basis of Libya's constitution.
"You are being deceived by the salaries, petrol salaries," al-Qadhafi said. "Yesterday I went to Sebha [town]. Oh, the shops, markets, cafes, restaurants and photo shops, it was glamorous!
"All the world's output that you could ever need was in Sebha. But who is buying these goods? ... No one but people with salaries coming from the central bank, the treasury, or from petrol."
Looming water shortages
Al-Qadhafi also said that - as in many Arab countries - Libya's fast-expanding population is rapidly using up its water resources.
"The oases deep in the south of the country will soon become a wasteland because the water will dry up and the palm trees will die, whereas the population will grow," al-Qadhafi said. "What will we do by then? Will we cry?"
Despite vast oil wealth, most Libyans remains relatively poor
"Now, we have to plan for this, because we have limited water, including the Great Man-Made River Project, which is expected to run out in several dozen years."
Libya's $25 billion Great Man-Made River Project pipes fresh water from ancient aquifers beneath the Sahara to the Mediterranean coast.
"The Arabian peninsula is living on [desalinating] sea water because there is oil, there is money. But once oil is over there will be no money, no desalination, and people would die."
Islamic leaders are 'medieval'
Al-Qadhafi, leader of one of the Arab world's most secular governments, has also criticised Islamic leaders.
"These days there are a lot of a dubious speeches and propaganda ... which some naive people believe in ... but we can counter them with the Holy Koran and with science.
"These speeches will soon be prominent in Ramadan ... When I switch on the TV and see a bearded man, and naive people calling him to ask for religious advice, I feel pity for him ... Now this is like Europe in the Middle Ages, selling indulgences."