Stay tuned for live coverage from 1200.
1201: And we're off. Brown starts with condolences for the fallen in Afghanistan, both soldiers and journalists. He also says that the world will support Haiti, in the wake of their earthquake.
1203: First question from Bill Wiggin, who says that we entered the recession with one of the highest deficits of any developed country - does Brown regret this? You know how Brown will answer ... and, sure enough, he says our debt is lower than France, Germany, US, Italy, Japan etc. That ignores how quickly our deficit has risen - and how our debt will soon overtake some of those countries.
1205: Brown says only solution to the situation in Gaza is an overall peace settlement.
1206: Cameron now. He also starts with condolences. His lead question is about whether "everything that can be done will be done" to ensure grit supplies. This may seem like an odd tack for the Tory leader to take, but the weather is going to remain a big story for the foreseeable.
1208: Brown rattles off a list of measures, and says that he's confident that "we can maintain the transport network". Cameron's next question asks what lessons can be learnt, and says whether they'll be a review. This is all very gentile so far.
1209: More lists from Brown. You wonder whether Cameron has a sting in his tail.
1210: Odd. A Labour backbencher is asking a question now. Will Cameron be back shortly?
1211: Questions, questions, questions. Is this a conscious attempt by Cameron to defuse PMQs, rise above the usual Punch 'n' Judy stuff, and seem more statesmanlike?
1212: Clegg now - he asks Brown whether he'll appear before the Chilcot Inquiry before the election. Brown says this is a matter for the Inquiry, and he will appear when they call him.
1213: Clegg responds by saying that Brown has a moral obligation to put himself forward. Brown responds smartly, saying that Clegg has also been saying that Chilcot should be able to decide how the inquiry proceeds.
1215: Couple of backbench questions on children. Brown talks about SureStart, investment, etc.
1216: Surprisingly forthright stuff from Brown, re. childcare: "There are people in this country who, we must admit, live chaotic lives - and we must step in to turn that around."
1218: Cameron's back now. He immediately kicks off with a reference to the "events of last week". So that's it: a split between the non-combative and combative stuff.
1219: Brown jokes that Cameron doesn't look like his photo on the Tory poster. He adds that Labour are about policy...
1220: Snappy response from Cameron - he asks how many MPs will put Brown on their campaign literature. All Tory MPs put their hands up, a handful of Labour MPs so the same. Cameron: "You've been airbrushed from your party's campaign"
1222: Cameron returns to an old favourite: getting Brown to admit that he didn't abolishg boom and bust. Brown waffles, as usual.
1223: The Tory leader is having fun with Brown's troubles. He refers to the Peter Watt revelations, specifically the quote about Harriet Harman writing policy. His question follows: will you join your Chancellor in saying that there will be severe spending cuts.
1224: Brown's response? Yep, you guessed it: do-nothing Tories, airbrushed photo, etc. etc. He seems to be concentrating on that Tory campaign poster. You can see the thinking: it's all part of the PR Man attack. But the problem is that more people are probably aware of last week's attempted coup than they are of one Conservative poster.
1226: Cameron sits down after one of the most (lightheartedly) Punch 'n' Judy exchanges for some time. There'll be questions about his two-part approach.
1228: Backbench questions again, now. Stuff on spending and the Western Sahara - as well as (what you imagines is meant to be) a Tory-baiting question from Gordon Prentice on non-dom parliamentarians.
1232: John Bercow has had to cut short about four meandering questions now.
1234: Christopher Chope asks Brown how he's going to prevent the UK population hitting 70 million. Brown doesn't say that this isn't likely - or deny the need for a cap - but., instead, refers to his goverment's points-based immigration system
1235: And that's it. Verdict shortly.
VERDICT: What a strange PMQs. Not only did we have Cameron's unusual two-part approach, but the second exchange between Cameron and Brown was one of the most jokey for some time, with both men on confident form. Did Cameron's tactic work? Well, I think he just shaded it. The Tory leader didn't quite administer a killing blow - but the fact remains that Brown's leadership troubles will have far more traction with the public than any quips about that Tory poster.