Edit Page option missing

Scenario:
On the default page you see the option to 'Edit Page' under Site Actions Menu but when you navigate to any List forms ( NewForm.aspx, EditForm.aspx , AllItems.aspx ), you dont see the option in the Site Action Menu

Reason:
Option is still available but intentionally hidden to avoid changes to those pages.

Work-around:
If you still want to switch to Edit Page mode, paste the following line into your Broswer's Address Bar.

javascript:MSOLayout_ToggleLayoutMode();