Don't know how much profit you may extract from this, but:
There is a company that is going public called Travelzoo. To enhance its
visibility, it's giving away 700,000 free shares of stock. Yahoo did the
same thing when they went public. You can get 3 shares right away and then
1 more for each person who uses you as a reference (up to 10 shares). Go to
http://travelzoo.com/menu1.asp and click in the upper right corner "Become
a co-owner" and keep clicking on "continue" until they prompt for your
e-mail address. After supplying this, they will e-mail you a few minutes
later with a PIN. Go back to their site (Copy and paste the address they
give you) and enter the PIN.
(Of course, you are welcome to enter email@example.com as a reference email)
Have you heard of other examples of such stock distribution? It seems a bit expensive for them...