a Nokia N800 click here
which I think has the edge over the Datawind in some respects, and costs about the same. The difference is that the Nokia needs a wireless network to be available in order to connect to the internet, but apart from that there are no extra costs.
Having looked at both devices I went for the Nokia, but the Datawind will certainly appeal to many. This is a market sector that will probably be quite active over the next year or so.