This was a question I was asked after a presentation about OLPC and Sugar that I recently gave at an Austrian university. And I had to smile because only 10 minutes earlier a slide had been projected on the wall that said ">800,000 XOs";-)
However given that I've been using that number for all my presentations in the past few months I started researching what the most current information on the number of XOs in the hands of children was.
A year ago the deployment-page on wiki.laptop.org was quite a reliable resource for that kind of information. However seeing that the page was last updated in mid-2009 and especially given that the row for Uruguay still talks about 40,000 XOs delivered, shipped and ordered when the actual number is closer to 420,000 XOs it's not really quite as good a source as I'd like (unfortunately I didn't manage to update the semantic entry with the new information...).
Now another bit of information that I remembered was this interview with Nicholas Negroponte at the end of October where he mentioned that:
OLPC has reached over one million children in 19 languages and 31 countries, with another million queued up to go to places like Gaza, Afghanistan, Haiti, Cameroon and Mali.
Now that's more like it. Especially given that combining the fact that Quanta has been producing XO-1s for 2 years now (did anyone celebrate the anniversary by the way?) and at least in early 2009 about 50,000 XO-1s were produced per month makes for roughly 1.2 million XO-1s having been produced to date.
Considering that it takes several weeks for these machines to travel around the world, make it through customs, go through any software customization or logistics stages before finally making into the hands of school children it safe to assume that approximately 1 to 1.1 million XO-1s are in use today.
By the way, based on current assumptions about global netbook sales in 2008 and 2009 - roughly 50 million all together - that means that OLPC's global "market share" within the netbook segment is approximately 2% - not bad for a small non-profit organization, ey? :-)