This is a small shredder carried in front of you with a strap around the back of your neck.
When someone comes up to you with a carefully prepared paper and says: "I was hoping you'd have time to look at this", you reply: "Yes, yes, very interesting." bzzzzzzzzzzzzz.
OK, it's not real, of course. It's a gadget occasionally carried by the pointy-haired boss in the Scott Adams Dilbert cartoons.
Like everything in Dilbert-world, though, it's only a slight exaggeration.
Lots of bosses, including those in schools, carry virtual Port-o-Shreds.
They take the form of a propensity to ignore, or even be rude about, ideas brought to them by colleagues.
You can see how it might happen.
There you are, experienced, seen it all before, been on the course, talked to the people at the curriculum development centre, clear about what's to be done. Then along comes Tiresome Terri with a naive plan dreamed up in the bath the night before.
"Sorry, Terri. Maybe I'll have a look, but really it's all been sorted and there's a lot more to it than you could ever know." bzzzzzzzzzzzzz.
As a result, Terri is disillusioned and less likely to come up with anything in the future. In terms of the development both of Terri and of your school, it's an own goal.
It doesn't have to be like that, however. There's plenty of evidence to show that the way to preserve the enthusiasm of good young teachers is to give them responsibility.
One of the great pleasures of visiting schools where good things are going on is to see exactly this in action - relatively new teachers being given space to develop ideas, led by heads and managers who then rightly enjoy the satisfaction that comes from nurturing talent.
Last term, for example, I was at Dartmouth school in Sandwell, where PE specialist Vicki Savage, just over two years into teaching, was telling me how she'd been made deputy head of Year 7 and was encouraged to develop specialist PE skills that no one else had.
"Girls' football didn't exist before I came. Now it's in the curriculum,"
A few months on, Dartmouth NQT mentor Anna Bennett tells me that Vicki has become acting head of year.
Anna goes on to give numerous examples of teachers with two to three years of experience now holding down management jobs, including heads of numeracy and literacy.
"Every NQT we've had for the last three years is now in a promoted post, either here or in another school," she says.
Sandwell seems to be good at this sort of thing. Down the road, in the same authority, Wood Green high school actually has an innovations unit, chaired by an assistant head.
"His job," says head Dame Enid Bibby, "is to find as much wonderful thinking as he can and see if it can be dragooned into fitting into school practice. He brings ideas to the leadership team, for us to argue about whether or not they are feasible."
So if someone wants to introduce a new curriculum subject, for example, there'll be questions about resourcing, staffing - and, importantly, what will have to be dropped to make room for it. It's a serious route, by which creative ideas can make progress.
The test of whether a school takes any part of its operation seriously is whether there's any funding involved. Dame Enid's innovations unit passes that one.
"We have a small amount of money in the budget, a bit of a magic pot, in case something needs to be supported," she says.
The big challenge in all of this - the ideal to which managers and leaders should aspire - isn't so much to make colleagues feel good and valued when their ideas are adopted (that bit's easy) but to maintain their confidence and commitment when their plans sink out of sight.
At Wood Green, people are clearly always going to feel that their ideas are being taken seriously.
"It's to do with emotional intelligence," says Dame Enid. "If you find time to sit down and say: 'It was a brilliant idea, but these are the problems and knowing all this would you go with it, if you were me?' then most people are happy."
For her, it's giving time and attention that's important.
"What you don't want to do is discourage people. A school only changes because of new ideas and we'd rather they came from inside than be imposed on us," she says.
Gerald Haigh is a former head who now writes widely on education matters