[TimothyBurgess]

What if I just add a place for visitors to donate and in return for donations I offer an arbitrarily small percentage of the company that just so happens to be proportional to the donation amount? Those who donate will just have to take my word for it. :P

[michael_dorfman]

That's exactly the kind of thing the Securities Act of 1933 is trying to prevent.

Seriously, talk to a lawyer. Or, at the very least, start reading up on Securities Regulations on Wikipedia.