I have started playing with facebook's graph api.
One question which seems to get asked a lot (since you have to know the answer to this in various contexts) is: what is my facebook id?
And I have seen a lot of bad answers to that question.
Here is a good answer:
Step 1: go to your facebook profile page.
Step 2: change the 'www' in the url to 'graph'.
Step 3: your user id will be in the result on the line that says: id: