Let's see if I can't add a bit more illumination in reply to Al's question.
Terry Fox was an up-and-coming university athlete who lost a leg to a rare form of bone cancer. While he was recovering from the surgery he got the idea of running across the country to raise money for cancer research. Contrary to what some believe, he did not make it nearly all the way; in fact, he stopped a little over half-way when the cancer spread to his lungs. The run didn't end with his death, either; he actually died 10 months later. He averaged nearly 40km a day during his run, and raised something like $23 million. (Ironically, a second one-legged runner *did* eventually run all the way across Canada. Next to nobody remembers him today, while Fox, who tried and failed nobly, is the hero.)
Sir Frederick Banting was one of three men who discovered the role insulin plays in controlling blood sugar (and thereby saved the lives of thousands or even millions of diabetics). He was killed in a plane crash during WWII.
Lester B. Pearson was no pacifist "pussy" -- he served in the Canadian Army during WWI. He is best remembered for introducing the concept of peace-keeping to the United Nations during the Suez Crisis of 1956. It could be argued that Canada has a much higher international profile thanks to Pearson than to any other Canadian politician of this century.
Sir John A. MacDonald was our first prime minister, a notorious drinker and a very smart politician. Those who've read a previous post in this thread should be aware that "western" Canada in 1867 meant London, Ontario. Most of the prairies didn't join Confederation until after Sir John A.'s death. To Canadians of the 1860s, in fact, MacDonald represented "western" (as opposed to Quebec and Maritime) interests.
Louis Riel was a "metis" (mixed French and Indian) political leader who led two different rebellions against the Canadian government. He was hanged after the defeat of the second rebellion in 1885. He's considered an important figure by westerners and francophones who resent the southern-Ontario establishment which ran (and arguably still runs) the country.
Sir Isaac Brock has been pretty accurately described already. Had he lived, the War of 1812 might have turned out rather differently (and certainly much differently than many Americans currently believe it did, but that's another story).
Tommy Douglas was a western-Canadian politician who is credited with being the father of Canada's system of socialized medicine. He was one of the founders of what became the New Democratic Party, Canada's social-democratic political party (currently a very marginal force everywhere but in parts of the west of the country).
Laura Secord did in fact make the famous 30km walk legend ascribes to her. For a while historians doubted the truth of the legend, but in the 1960s (I believe) three different testimonials were uncovered by the British officer (FitzGibbon?) to whom Secord delivered her message. Curious fact: Secord was actually born in the US.
Billy Bishop: I know nothing about this guy at all. Who he?
Nellie McClung was a lawyer (eventually a judge) and feminist activist. In the 1920s she led a group of women who sued over the rule in Canada's constitution that women were not "persons" in the eyes of the law. More controversially, McClung was also a firm believer in eugenics. Largely thanks to her, it wasn't until the early 1970s that the province of Alberta stopped sterilizing the mentally ill or deficient.
Here endeth the history lesson. Aren't you sorry you asked, Al?