Concrete Pencil: Just giving, or taking the mick?

People can take change, but it would be a brave giver who put in a twenty and took back a tenner, a fiver and £2.50 in shrapnel.

Some have put in coins, clearly - no small denominations though. Anything under £4 is probably indecent. But you're two days short of payday, and Birleys' beef and cheddar sandwiches aren't getting any cheaper.

So you calculate. How much do you like this person? Are they the colleague you sit next to when you've got a choice? Someone you go to the pub with, or see outside work, or has been to your house? Are they an acquaintance you tolerate? Someone you actively dislike?

Then you have to ask yourself how significant is the occasion? Just had a baby - they're probably doing all right for clothes and presents and stuff. £3.

Going for a better-paid job elsewhere? Damn them. £0. Their only gift shall be the jealousy in the eyes of the ones who had to stay behind, in the words of Morrissey (who I bet is one of those who would sneak in 20p just to make a sound).

Big birthday, retirement or redundo, that's when you really feel the pocket pinch.

The last factor: Is anyone looking?

At least then you have a chance. Not a sponsorship form: names and numbers, there for everyone to see. 

And if the marathon runner or head shaver or parachutist is wise, they will give it to a good friend first and land a nice big shaming £20 at the top of the list. 

They should avoid their absolute best friend because we'd take off as much as 40 per cent for that kind of relationship.

No, it has to be someone with whom they share mutual respect, who has a bit of cash about them or a special, secret interest in the cause being run, shaved or jumped for.

And it doesn't finish there. These days it's not just people in the same open-plan as you.

Now everyone you've ever known, all those ill-advised acquaintanceships you built up on Facebook, they can send you a link to Just Giving.

And there's no anonymous plunk of small change there. Your name, your total and a little message of support for these selfish, awful people.

(Obviously they're not selfish or awful. You are.)

You could lie on the form. But that's probably quite bad, no?

What if we all did these things? Do they ever think of that, these race runners and bikeathon, Great Wall of China charity holidaying freaksacks? 

If everyone you knew on Facebook did it, and you did it, we'd each owe each other £20. If you have 200 Facebook friends, that's £4,000.

And loads of charities would get loads of money. Which, on sober reflection, would be a good thing.

Now, who'll give me what for my sponsored shoe juggling?