Hello LebGeeks =)
Gnash :

Gnash is a media player for playing SWF files. Gnash is available both as a standalone player for desktop computers and embedded device, as well as a plugin for several browsers.[3] It is part of the GNU Project and is a Free and open-source alternative to Adobe Flash Player.[4] It was developed from the GameSWF project.[5]

Gnash was first announced in late 2005[6] by software developer John Gilmore. The current maintainer is Rob Savoye.

source : https://secure.wikimedia.org/wikipedia/en/wiki/Gnash

Gnash Debian Packages : http://www.getgnash.org/packages/

add This key ( through terminal ) :

wget http://getgnash.org/gnashdev.key -O-|sudo apt-key add -

then Go to terminal , and write

su

then write your root password ( you wont see it )
once you're in root access write the command below :

gedit /etc/apt/sources.list

and window will pop up , write at the end of it

deb http://www.getgnash.org/debs/debian squeeze main

Save the file , open a new terminal and write

aptitude update && aptitude install gnash browser-plugin-gnash

Eh voila! its done.

Gnash isn't like adobe flash player for sure . you can enable Html5 on youtube and watch vids without even having a flash player through this link : http://www.youtube.com/html5

and adding Flashvideoreplacer firefox ( iceweasel ) addon through this link : https://addons.mozilla.org/en-US/firefox/addon/flashvideoreplacer/

We hope , website becomes flash free in the near future .

Best Regards.