Rosé de Pressée, also known as the white wine method or skin contact method, sees the grapes crushed first and then the must (pulp and juice slurry) left to macerate for some amount of time before being pressed. The color is determined by the length of skin contact.
The third method is simply adding some red juice or wine to white juice or wine. It's illegal almost everywhere in the old world, with the exception of Champagne where it's traditionally used as a dosage to make rosé. There was a movement to allow this method in Provence, but it failed. As for the new world, I cannot say with certainty how and where it is used. I haven't researched enough yet.
My problem is with the differences between Pressée and Saignée. All textbooks make a distinction, but what is the difference in flavor? Several hours of trolling through the interwebs have uncovered only a handful or producers who even disclose their method. absent some source to explain the taste difference to me, I need a few dozen examples of each to figure it out for myself. I need that many to control for about a million other variables like terroir, year, house style, grape, et cetera. This one is tough. If anyone has leads, please do contact me. Otherwise, I feel a tasting coming to my house in the near future!
photo credit: http://en.wikipedia.org/wiki/Ros%C3%A9