This link is to a segment from the Rick Mercer show, doing a humorous take-off on the rules that first came from Transport Canada after the Christmas Day attempted bombing.
Last weekend, I flew from Toronto to Seattle on Air Canada. I was only allowed to carry my small purse and checked my RS rolling suitcase. I went through the usual security screening, then had a second screening, including a pat-down, just before I went to the gate. My purse was also thoroughly searched. I had a magazine, a book and my knitting in a plastic shopping bag - this was also carefully searched.
Once we were in the air, nothing was mentioned about any other security measures. I was able to knit, read and watch the movie right up until the plane arrived at the gate at Sea-Tac airport.
The latest update from Air Canada is that one carry-on bag is allowed on the plane now, with a small personal item, i.e. purse. The news tonight showed the body scanner installed at Pearson airport in Toronto - not sure if every person will be required to go through it before going onto a flight to the U.S.