Try using:
<h:inputText label="First Name" value="#{flash.firstname}"/>
<h:inputText label="Last Name" value="#{flash.surname}"/>
In your next page use:
<h: outputLabel value="#{flash.firstname} #{flash.surname}" />
Then you can access the value in your bean with:
Flash flash = FacesContext.getCurrentInstance().getExternalContext().getFlash();
setFirstname ((
String) flash.get("firstname"));
setSurname ((String) flash.get("surname"));
You may have to use #{flash.keep.firstname} in your EL expression in your page tag though. I'm not sure. Using the "keep" function in the flash tag attribute allows the saved data to stay through another iteration of the view lifefcycle. It will take the data from one page view to the next only unless you use 'keep' to maintain it. You'll have to look into it, but I think this points you in the right direction to do what you want. Atleast this is one way.
Good luck,
Mark