Thanks @chillbear, that's interesting, a bit more like freebase, dbpedia etc. But very US-focused and perhaps a bit forbidding to kids.
I would also wonder about data protection type concerns in using public services, as I would imagine kids will want to create data models that are meaningful to them, contain information about their lives.
Another problem in using something like Socrata, or Google Spreadsheets etc, is that everyone needs to sign up, kids won't have in-school email addresses or be able to access their out-of-school ones in the classroom.
I also saw this yesterday, knowledge-mapping software developed at the Open University - read some blog entries from parents who had been using it to structure arguments with their own kids, to persuade them why they could not get another cat!
The Open University : KMi : Compendium : Screencasts
That has a lot more appeal to me than "let's arrange data in a table, sort it in different orders, and press a button to draw a bar chart" - which might as well be a paper exercise, or a few lines of Logo. Mind mapping, linked data, social graphs, etc - the information processing world seems to have moved on a bit since the national curriculum for IT was last updated in 2000
@michael - Mum wants to find something free for economic reasons - but I would like to find something free for ideological reasons.
I am amazed at the responsiveness and helpfulness of this forum - I will have to find an excuse to stick around - hoping to make it down to BETT for a day, just to indulge my growing curiosity about the world of software for schools.