The only FXG editor I\'ve seen for Flex is by 7jigen, works online or as a Flex app.
Does anyone know of a different one? It can be done in Illustrator I think, but
I have used this process to generate a ton of FXG assets that I have imported into my Flex projects.
1. Draw the shape in Flash CS5
2. Break the shape apart (Ctrl+B)
3. Select the shape
4. File -> Export -> Export Selection
5. Save as FXG
You can then import them directly into Flex and voila! Good to go!