Adobe Flash Player 11 stable has been released. Along with other improvements, most importantly, this version natively supports 64-bit Linux OS. Other features include:

http://www.tuxgarage.com/2011/07/adobe-flash-player-11-beta-both-32-and.html
If you are running some other Linux than Ubuntu, you can safely follow the instructions under the section "Manual Download and Installation (32-bit and 64-bit)" there.

- Stage3D APIs � Create highly interactive visuals to improve collaboration on 3-dimensional models.
- 64-bit support � Support for 64-bit operating systems and browsers on Linux, Mac OS, and Windows.
- G.711 audio compression for telephony � Integrate voice/telephony into business apps using G.711 codec.
- H.264/AVC SW Encoding � Encode higher quality video locally using H.264 video.
- Socket Progress Events � Build advanced file sharing apps like FTP clients that send large amounts of data.
- HD surround sound � Deliver full HD videos with 7.1 channel surround sound directly to AIR powered TVs.
http://www.tuxgarage.com/2011/07/adobe-flash-player-11-beta-both-32-and.html
If you are running some other Linux than Ubuntu, you can safely follow the instructions under the section "Manual Download and Installation (32-bit and 64-bit)" there.
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