Visit the Official Site

Slide Show:
From the Main Menu, select Scene Selections. Then, choose Scenes 13-16. Select the thumbnail for 15 (bottom left), then press you Left button. You will see a red wine bottle icon. Hit enter and you will be treated to a three-minute slideshow (with music) on the making of Sideways.
Reported by: Phil Nigash

DVD-ROM Bonus Feature:
You will need to play the DVD on a computer with a DVD-ROM drive to see this Easter Egg. From the Main Menu, access the "Special Features" option, then the "Deleted Scenes" option. Move your mouse over the right eye of the Virgina Madsen Charicature (the middle one) until the mouse pointer changes, then click. This will reveal a parody of "Project Greenlight" called "Project Searchlight".
Reported by: Gary Bass

U.K. Egg Differences:
A PC is not necessary to to access 'Project Searchlight' (not on the Region 2 edition at least). From the deleted scenes menu, press 2 then 10 on your remote control.

Also, as well as the slideshow, there is 13 minutes of outtakes: go to the Language Selection menu and press 2 then 27 on your remote control.
Reported by: Jim Williams