Campaign Finance, Corporate Free Speech, and Television

I currently live in Pittsburgh, which was the location for a recent NPR report on campaign ads financed by corporate money. Indeed, when watching television these days, sometimes literally the only commercials are either for the networks own shows or for/against a political candidate. This has caused me to go back and reexamine my thoughts about the Citizens United decision, and to think about the relationship between campaign finance, corporate free speech rights, and television. These are my thoughts, and I'd be interested to hear yours.

Should corporations have any free speech rights?

I would have a lot of trouble saying that corporations have no free speech rights at all. If Corporation X wanted to spend its money publishing and distributing a book every two years right before election day that evaluated every member of Congress, I would be hard-pressed to find such activity unprotected. The idea of banning books or pamphlets of any sort bothers me a great deal (as would banning any modern electronic versions of such things). However, is this just instinctive revulsion to the idea of "banning books"? Could I make a constitutional argument that banning corporate books is not protected speech?