If you are wise, attractive and generally wonderful enough to have already acquired a copy of Inflight Science you may be puzzled and be saying 'But it was already a paperback'. This reflects the way the first edition was in a rather strange format called 'trade paperback' which is half way between a hardback and a paperback. (See this post for more info on the concept.) What has now come out is the mass market paperback version. This is smaller and cheaper than the original - so even handier to slip in that pocket prior to a flight.
Unfortunately the publishers in their wisdom (and I'm assured there is a good reason) have only brought this version out in the UK - so in the US there's only the trade version, which is also still available in the UK, as it's rather snazzier to buy as a present. However, the Amazon.com price is very good on the chunkier version, so it's not too much of an issue.
So there we have it. Even more choice of Inflight Science possibilities. Even more affordable. What's not to love? Check it's web page for more info.