What's hot in the world of science?

I've just discovered the nifty new "Most Popular Now" page on BBC News, which shows you which stories are getting the most attention worldwide, or region by region. You can even check by subject - for example, as I write the top science and nature stories involve a 'chameleon' snake and another depressing set-back for the EU emissions trading scheme (though it's Germany, rather than the UK, in the dock for once).

Wouldn't it be good if instead of the general public, you could discover what was exciting scientists? Nature offer a list of the month's ten most downloaded articles, but sadly (and not surprisingly) biomedical stuff seems to dominate to the exclusion of all else. Better is the Top25 portal at ScienceDirect, where you can search by subcategory and individual journal (I think you can at least access the abstracts of the listed papers without a subscription).

This is a very crude tool, because a better measure of whether a particular paper has excited scientists is how much they use the ideas and results to guide and augment their own work, which is measured by citations. Tracking who is citing whom is a bit more difficult than counting downloads or page hits, so freely available information seems a bit limited: Thomson Scientific runs in-cites, which offers the top three 'hot papers' published in the last two years in various fields, and also a list of 'super-hot' papers which seem to be garnering special attention. However, although this is interesting, I don't know how much use it is for me as a scientist - within my field I can learn a lot more by getting down and dirty at Web of Knowledge, and searching for papers in the Science Citation Index, which cross-links every paper published in the last 25 years to the ones it cites and the ones it is cited by. Having an internet connection on my desk is a mixed blessing, but every minute of my day that is wasted through mindless web-surfing is more than compensated for by access to that sort of information.