He said a Conservative government would "seriously consider" the possibility of fixed-term parliaments - which would end the right of the government to choose the timing of elections.
"If we want Parliament to be a real engine of accountability we need to show it's not just the creature of the executive to be dissolved on the whim of a prime minister," he said.
But he said he would not consider a move towards proportional representation because he said that meant party managers - as opposed to voters - would end up choosing a government "on the basis of secret backroom deals".
He pledged an end to policies "dreamt up on the sofa at No 10 Downing Street", more transparency by limiting the number of special advisers and to strengthen the independence of the civil service.
A Conservative government would ask the Boundary Commission to look at reducing the House of Commons by, initially 10% and make sure constituencies were the same size, he said.
He also suggested legislation was published online in a more digestible way, Parliamentary proceedings put on YouTube - and said people could get "text alerts" when issues they are interested in are debated in the Commons.
The expenses of all public servants paid more than £150,000 a year would be put online - as would all public spending over £25,000.
"Just imagine the effect that an army of armchair auditors is going to have on those expense claims," he said.
"Indeed, the promise of public scrutiny is going to have a powerful effect on over-spending of any variety. "
Other issues the party will look at include possible curbs on the whipping of votes - when MPs come under pressure to toe the party line - in considering bills line-by-line at the committee stage.
MPs would also be handed the power of deciding the timetabling of bills and backbenchers would get powers to choose the chairmen and members of select committees.
The use of the royal prerogative which allows the prime minister, in the name of the monarch, to make major decisions without the backing of Parliament, would be limited.
Ken Clarke, who headed a recent Conservative taskforce looking into constitutional reform, said Mr Cameron's proposals were meaningful and would significantly enhance Parliament's powers.
He told Channel 4 News that he would support fixed-term elections as long as they was a provision for a Parliament which was deadlocked or had lost its authority to be dissolved.
'Nip and tuck'
Justice Secretary Jack Straw welcomed Mr Cameron's comments but said many of the ideas had been around "for some time" and there was always a gap between rhetoric on the need for constitutional reform and what politicians could actually deliver.
"What's important is that there is now a growing consensus in favour of many sensible changes," he said.
Labour's achievements included the introduction of the Human Rights and Freedom of Information Acts, he said, as well as progress on reform of party funding and a proposed bill of rights.
If we rely on turkeys to vote for Christmas, ministers and MPs will never give up real power
Asked about the possibility of giving voters the power of "recall" - to sack their MP mid-term if necessary - Mr Straw said it had been suggested for the House of Lords last year.
As MPs were elected for a shorter period, it had been felt that elections were sufficient to hold them to account but he added: "I certainly think it should be looked at."
However, he distanced himself from the idea of a referendum on the electoral system at the next election - a plan floated by Cabinet colleague Alan Johnson - saying it should not be "confused" with the wider issues at stake at the election.
Mr Straw also warned that electoral reform would not be a solution in itself, for the damaged reputation of Parliament.
The Liberal Democrats, who favour proportional representation, said Mr Cameron's plans did not go far enough.
Party leader Nick Clegg told the BBC: "David Cameron's ideas really don't go far enough. They are not a shakeup of British politics, they are a sort of nip and tuck of British politics.
"They say nothing about giving people the right to sack their MPs if they have done something seriously wrong.
"They say nothing about the scandal of having a House of Lords which can make the law of this land, but no-one elects them."
The Local Government Information Unit, a think tank that supports councils, said Mr Cameron should commit to "a massive rollback of central government".
Chief executive Andy Sawford said: "Whitehall is bloated, Parliament is bloated, MPs' expenses are bloated, and we have to burst the bubble.
"Talk of radical decentralisation is welcome, but this kind of rhetoric has been around for years. If we rely on turkeys to vote for Christmas, ministers and MPs will never give up real power."
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