A celebration of chemical reactions, sensible and simple advice, and some much-loved cookies.

To celebrate the international year of chemistry, Central Science, the C&E News blog, launched a blog carnival on an unsuspecting world (http://go.nature.com/L7tg9T). Rachel Pepling requested posts from anyone, from “Big name bloggers and fledgling writers”. The theme? Your favourite reaction. The lure (apart from the fun of the carnival itself)? The best posts will get published in C&E News. That bait proved hard to resist, and many regular bloggers rushed to contribute. Reactions ranged from the Mukaiyama thioester synthesis (ChemBark, http://go.nature.com/mRY6Io), not one but two on the Diels–Alder reaction (BRSM, http://go.nature.com/rcU33v, and Azmanam at the Chem Blog, http://go.nature.com/WIJBlJ), its cycloaddition partner the azide–alkyne Huisgen (Shannon Morey at Chembites, http://go.nature.com/ExZIcT) all the way to the oscillating Belousov-Zhabotinsky reaction (Jyllian Kemsley at the Safety Zone, http://go.nature.com/YFR2DL). You can read David Kroll's final round-up post at Central Science (http://go.nature.com/jQbZmp).

How good are your data habits? Doug Natelson poses this question in a post at Nanoscale Views (http://go.nature.com/by1BXk) that covers a lot of ground in data management and note taking. Some of the good stuff: “Everything is data” and “The data are the science”. “If you didn't document it, you didn't do it”, so “Write down everything” and then “Back everything up”. Sometimes simple advice is the best and, as Natelson says, “I guarantee, you will never, ever in your life look back and say, 'I regret that I was so thorough, and I wish I had written down less'.”

And finally....do you like chocolate chip cookies? Do you like them enough to make 268 of them in order to perfect the recipe and make them just like your grandmother did? Well, Deborah Blum obviously does, because that's what she takes us through in her post at Speakeasy Science (http://go.nature.com/7P36rJ). A tasty read we can highly recommend.