LinkedIn lets you see who looked at your page, but only if you agree to make your own viewing public too. Lucky for us creeps, you can turn public viewing on just long enough to see who looked at you, then turn it off.
On the home page, click "See who's viewed your profile!" on the right-hand side.
LinkedIn has set you by default to "semi-anonymous," which means you can't see the names of the people who looked at you, but they can see just where you worked.