By Martha Kearney
Presenter, BBC Radio 4's World at One
What a glamorous week!
Even Bob Geldof was star struck at the global gathering
Michelle Obama taking London by storm in an array of beautiful outfits.
Police outriders escorting world leaders across town in gleaming cavalades.
The birth of a new world order, we were told.
It did not seem quite like that to us journalists at 5.30 on Thursday morning at Peruvian Wharf in London's docklands.
We had to sit for an hour in a dirty bus before we were transferred to a clean one.
This was not about clearing up crisp packets or fag ends but spook talk for vehicles inside and outside the secure area.
Low key atmosphere
In fact the whole landscape looked like one of those locations in Spooks where Harry hands over a terrorist to the Russians.
Even at the heart of the summit, the atmosphere was distinctly low key as Bob Geldof told me in a PM interview: "You look around and think, oh yeah, that's Manmohan Singh, leader of a billion people. Or that guy, chewing on a sandwich, he's Hu Jintao, the President of China."
Obama's earlier apparent snubs to Brown were forgotten
The Excel centre was clearly a sensible place to have the G20 summit from a security perspective but it had also been picked for a symbolic reason.
Just as the Docklands are the site of East London's regeneration so Gordon Brown hoped his summit would find the means of regenerating the wastelands of the global economy.
Late on Wednesday night his people were already bubbling with optimism about the outcome.
They felt they had achieved the almost impossible by transforming what had been a shopping list of 47 items after the last G20 summit into a coherent plan.
The aim is to channel money to emerging economies which are an engine of growth across the world.
The fact that their markets have seized up has created immense problems for export-led economies like Germany and Japan.
More money will be available to them in a number of ways - through new trade credits, a trebling of funds to the International Monetary Fund and a new allocation of Special Drawing Rights, a form of international money that can be printed by the IMF.
The 1.1 trillion dollars in total was far more than had been expected, Gordon Brown placed the agreement in a Biblical setting as befits a son of the manse.
"The world will no longer pass by on the other side", he said.
But there are questions to be asked about the money, in particular about the role of the IMF, a body which has come under a great deal of criticism in the past.
I interviewed Ha-Joon Chang, one of the world's most eminent development economists on Thursday.
His view was that the IMF had always been opposed to deficit spending in the past so would find it difficult to reinvent itself as an engine of fiscal stimulus.
Bob Geldof too was worried about the kind of conditions which are normally imposed by an IMF loan.
I put those points to Mark Malloch-Brown, the Foreign Office minister who has been one of Brown's chief negotiators.
He acknowledged that the IMF would have to undergo a process of reform.
There were setbacks too for the Obama/Brown axis as no agreement was forthcoming about a future commitment to more fiscal stimulus.
Instead there was praise about the five trillion dollars already committed for this year and next.
The government argues that the summit has acted as a spur, a deadline for individual countries to act.
But it is highly possible that they would have decided to increase spending and cut interest rates whether there was a summit in the offing or not.
For Gordon Brown himself, the summit has been a triumph as was evident from his body language throughout.
Long forgotten were the apparent snubs from his Washington visit as President Obama lovebombed him with praise.
But what good will all this do him domestically?
To some he will have demonstrated statesmanship and proved that his experience in a crisis can be trusted unlike the "novices" of David Cameron and George Osborne.
But others may resent the time he's spent hobnobbing with foreign leaders when there is so much pain and trouble at home.
At the final press conference, the prime minister was powerful when speaking about poverty around the world.
He was less compelling when trying to relate the actions of the summit to people's real lives in Britain.
For this to be any kind of springboard for a political recovery, he will have to find the language to do so.