Conditional compilation Or share class file between 2 packages

[]There is no way to have conditional compilation in flash, but I just wanted to make sure that this is true. And does anyone have any workaround for that ?
]I have 2 applications that share common files. Changing code should reflect in both the applications. So I have to copy and paste everytime I change something , even a word…
[/list] [indent]I have one solution that I can breakup my package and create 3 packages 2 for 2 applications and 3 that has common files shraed by 2 applications.
[/indent] [indent]I wanted to know if this is a good solution or can there be any other solution to this ?