Thousands of people remain stranded as restrictions on flights in European airspace extended into a fourth day because of the cloud of ash from a volcano in Iceland.
BBC news website readers across the world describe their predicaments.
HELENE SVENDSRUD, NORWEGIAN IN HONG KONG
I am stuck in Hong Kong, en route from Bali to Oslo.
Helene is enjoying her unexpected stopover in Hong Kong
I'm currently in a five star hotel courtesy of Cathay Pacific with all the other passengers who were on the plane.
We are very lucky compared to some others around the world.
Cathay Pacific have been excellent: there has always been at least one representative in the hotel, ready to answer our questions. They organise regular gatherings to give us information and they ring the hotel room of any passenger who isn't present.
The latest is that we'll be here until Tuesday - we're now getting our luggage delivered. If anyone wants to return to their starting point, Cathay Pacific will pay for that trip, but then you have to pay your own way home.
I don't have anything specific to go home to in Oslo. I was in Bali visiting friends I made when I was a student there last year, so, depending on what happens on Tuesday I may return to Bali.
There are quite a few other Scandinavians in the hotel, so I'm going shopping with them, walking around, trying to do fun things.
PARISSA, IRANIAN IN LONDON
Parissa and her mother are saving money by eating one meal a day
My mother and I arrived in London on Thursday with Virgin Atlantic, after visiting family in the US for a couple of weeks.
Our connecting IranAir flight to Tehran was due to leave eight hours later, but we are still here. There's no alternative way of getting home.
British officials gave us a seven-day visa and Virgin Atlantic gave us one night at a Premier Inn hotel, but after that - nothing.
We stayed there another night but it was too expensive, so we moved to this cheaper hotel near Heathrow. Our family in Tehran found it for us after looking on the internet.
IranAir tells us we may be waiting four or five days - or maybe three weeks. We can use our ticket, but we don't know when.
I've never been to London before! But our money is running out so we are eating just one meal a day. Perhaps our family in Iran will wire us some money via Western Union. We just sit in our room, watching the television news.
Nobody has explained what is going on, we will try contacting the Iranian consulate tomorrow.
I feel bad! Bored, worried and exhausted. A work colleague rang from Tehran today to ask where I was. I said I was stuck and didn't know when I'd be back.
MAYANK SHARMA, BRITON IN LAGOS, NIGERIA
Mayank says he is bored of watching CNN on his hotel room TV
I have been stranded in Nigeria since Friday and BA has done nothing to contact any of us!
I rang BA and asked why they were not making any hotel arrangements for us and the woman said: 'It is an act of God and we are not responsible!'
I said "You don't really expect me to believe what you're saying?" and I was told "Yes, we do". So, I ended the conversation - what if I were an atheist?
I am here on business, I'm a supply chain consultant. My client has said it will pay my hotel bills, but then they want me to work for free when I return to London.
We've been advised not to leave the hotel for security reasons. There's nothing to do really, apart from watch TV or go online.
Right now, I'm booked on a flight to London next Saturday. I'm just hoping the skies clear up.
CARLOS VEIGA, PORTUGUESE IN KUALA LUMPUR, MALAYSIA
Carlos is not enjoying his unexpectedly long first trip to Asia
I was working in Singapore last week and spent the weekend in Kuala Lumpur, where I'm now stuck, as my flight back to Zurich was cancelled.
I'm flying with Emirates and I need to change in Dubai to get to Zurich. Emirates have managed to find me a seat on the 22nd, so let's hope the airport is open by then.
This is my first time in Asia, but I was really looking forward to returning to Europe and I don't feel like going out and seeing things.
My company is footing the bill - I'm not here on holiday! They have an office here in KL so at least I can go in to work tomorrow. The office is in the Petronas Twin Towers, so I'll make the most of that.
I keep checking Google news to see when the Swiss air space will reopen. I do wonder if the airlines are being overly cautious, but I'm not in a position to know.
LARS ERLEND OYMO, NORWEGIAN IN BELGIUM
Lars is getting to spend more time with his girlfriend in Belgium
I'm currently stuck in Belgium, waiting for my flight home to Oslo. I'm visiting my girlfriend.
My Ryanair flight was due to leave at 11 o'clock on Friday, and I've finally managed to rebook it for Tuesday 20th.
Ryanair are so busy it's hardly worth calling, so I rebooked online.
I'm still not entirely sure if I'll make it home: Norwegian newspapers say airports in Norway will probably stay shut until Tuesday.
I'm pretty well off considering. We're now visiting my girlfriend's family and we'll return to Brussels tonight.
But I'm a university student and I need to get back to study for my exams.