When people bring up grandfather paradoxes as an argument against time travel, I wonder why that needs to be the case. Just because the human mind runs into a logical paradox, does that have to be the case in nature?
You can throw out causality if you wish, but then you have to throw out all of science with it. That's why time travel stories that invoke paradoxes are pure fantasy. I explain some of the cop-outs in another thread
Sorry, ebusinesstutor, but I stomp on PASTWATCH as an example of a bad time travel story. You might want to try James P. Hogan's THE PROTEUS OPERATION. It is very finely detailed, has an excellent cast of characters, and lots of wild sci-fi ideas. And no paradoxes.