Get out your Widow Twankey costume for Ethiopia

You could tell the people running the London Marathon for charity. They were the ones carrying plywood Spanish galleons strapped over their shoulders. "In aid of the British Heart Foundation" said their T-shirts as they lay wheezing on the roadside while St John's Ambulance checked to see if they'd given themselves a coronary.

For some reason it has become the accepted convention that people raising money for charity are compelled to dress up in stupid costumes. Why is it that giving up time or money also requires us to surrender our dignity at the same time? "Thousands are starving in Ethiopia so I'm going to sit in a bath full of baked beans and do a sponsored singathon of Abba hits." The Bible does not say what Jesus was wearing at the feeding of the five thousand, but I can't imagine he dressed up as a pantomime dame, stuffed two balloons under his shirt while all the Romans looked on with a smile, saying, "It's alright; it's for charity."

Perhaps being madcap and bonkers is a way of coping with the awfulness of the suffering to which we are drawing attention. Occasionally, the problems seem so huge that we just want to put them out of our heads altogether. We pretend we're doing enough for charity by buying a lottery ticket, and reassure ourselves that if we won the jackpot we'd give a lot more.

But the fact is that we all won the lottery on the day that we were born. We rubbed the little silver bit on the scratchcard of fate and it came up with "Middle Class, Britain" and we punched the air and shouted "Yes!" The bloke next to us rubbed his coin on his scratchcard and saw that he'd got "Peasant, Horn of Africa". "Oh bad luck mate. I might as well take that coin off you before you go."

But despite our enormous good fortune some of us are still reluctant to give a little of our comparative wealth away. This might be because we have an aversion to medical students collecting for Rag Week dressed as characters from South Pacific. But it is more likely that we have a deep-seated fear that we may be being taken for a ride, that we may be giving a pound which won't get to it's intended destination. But isn't this a risk worth taking?

Even if it were true (which it is certainly not) that only a fraction of Third World aid gets through to those who really need it, 10 pence would still be worth much more to the intended recipient than the original pound was to you. In fact, with emergency relief, every penny generally goes straight to the famine-hit areas. The Red Cross, for example, are running daily flights carrying maize and soya directly into the worst- hit areas. (The airline food stays on the plane; the Ethiopians have already suffered enough.)

The Oxfam fact sheet in front of me says that pounds 2 buys enough seed to plant a whole acre of sorghum in the Sudan. Okay, I don't actually know what sorghum is - it could be local slang for cannabis - but it still sounds like a bargain. What else can you get for two measly quid? Seven minutes parking in central London. A disappointingly small packet of cashew nuts. One unfunny greetings card. As I write, my kids are stuffing their faces with an Easter egg that cost pounds 3. The same amount could pay for a girl in Bangladesh to go to school for three months. Admittedly the girl in Bangladesh would much rather have the big chocolate Easter egg but that's besides the point.

Yet many people will only give to "good causes" if they can personally witness the benefits of their own largesse. In reality the good cause is their own ego. A friend of mine showed me his latest copy of the magazine sent to alumni of Westminster School. It proudly reported that a former pupil has just given pounds 1m to his old school. "Hmmm," this old boy must have thought, "Who can I think of who really needs a million quid? Starving Ethiopians maybe? Flood victims in Mozambique? Children with leukaemia?" No, he decided, "Clearly it has to be Westminster School, where all those poor children of merchant bankers and Tory MPs are having to get by with internet access limited to off-peak hours only." What more deserving cause could there be?

But unless thousands of emaciated refugees are massing on the cricket pitches of your old public school, I urge you to make a donation to Ethiopian famine relief now. Don't make an excuse to yourself; nothing but good can come out of any donation you make. Remember, pounds 1 keeps guilt at bay for a whole day, pounds 10 will pay for a whole week of smugness, and pounds 50 guarantees a whole year of sanctimoniously refusing other charities. So please ring one of the numbers below. And remember this is for charity, so don't forget to put on your Widow Twankey costume before you make that call.

Credit card donations: Oxfam 01865 313131 Red Cross 0870 444 3444