This is the Thinking Day ceremony I used to use with my Brownie Pack in England (Brownies are aged 7 - 10 in the UK). It certainly isn't the ceremony that all British Brownie Packs use for Thinking Day - I don't think such a ceremony exists! - it was originally the ceremony my Mum used to use when I was a Brownie in her Pack, and is one of those wonderful timeless ceremonies that keep their magic no matter how long they've been around. When I have used this ceremony as a Brownie Guider, it always seems to make an impression on the Brownies.
The Brownies sit in a circle. In the middle is a picture of the World badge, map of the world, or anything else you think is appropriate.
The Leader begins by talking about what Thinking Day is, why it is February 22nd, and how there are Brownies in lots of countries across the world. If you have a picture of the world badge, it is also an ideal time to introduce it to the Brownies, explain who can wear it and why we wear it, and what the different parts of it mean.
I've found the best way to keep the Brownies' attention at this point is to approach it as a question and answer session - plus the older Brownies love the opportunity to show their knowledge. (It also gives you, the Leader, a bit of a boost because you feel as though you have taught the Brownies something in the past!)
For the second part, each Brownie is given a nite-light (small, short, fat candle!) on a foil tray. Note: it may be a good idea to check that anyone with long hair has it tied back, and also that no one is wearing loose clothing that may catch alight (for example neckerchiefs/scarfs).
An adult (or sometimes, even an older responsible Brownie) lights all the candles, and switches the lights off. This is also a good point to demonstrate how to light a match and candle!
Each Brownie is also given a piece of card with the name of a country on it that has Guides / Girl Scouts. In turn, each Brownie picks up her candle and card, walks to the middle of the circle, says 'I'm thinking about Brownies in … ', put the candle and card down, and goes back to her place.
(One variation I have heard, is to light the candles one by one in the middle of the circle, so that they don't have to be carried.)
At this point, each Brownie can also give in her donation (traditionally a shiny Thinking Day penny) in to a pot. The leader finishes off by thinking of all the other countries in WAGGGS, and scattering the names all around the circle of candles (the Brownies are always impressed by how many countries there are!).
At the end of the ceremony, sing songs by candle-light - my Brownies always remember this bit the most, and the Parents were equally impressed when they came to pick them up.