Has anyone got any suggestions for perhaps near professional applications available for designing on linux?

I regularly use Photoshop and Dreamweaver as well as Flash and Fireworks and it would be good to have a look at a linux alternative.

Perhaps they could be emulated? I own Flash but I am saving for the others. I work with them all every day at work though so I am not too keen on relearning how to walk after learning so much about the windows apps.