1. I think back in 2001, it cost like $130 a person to do the walk
2. It takes a long time
3. You put on a big great coverall suit, and then latch yourself to the bridge rail (something like that)
4. You can't bring your own camera (because it might fall into traffic). But there is a photog who takes official pics of everyone at the top. Not sure if that is included with the package, though.
Even if you don't do the above, you can go across the bridge and climb up one of the towers there and look out. I'm pretty sure I have a shot of Mrs. Mohandas standing out there, and it's one of my favorites of her.