Well, if you want to create pdf from adobe flex or adobe air, you could buy a Adobe LiveCycle Data Services copy
but you could also try the same thing with the open source library AlivePDF.
Heres a small example with text and image possibility.
But remember you can use the save button only when you have Flash 10 installed.
Click here for the source.
Oh and line feeds of carriage returns are a problem 😉