The decision has already been made, there's no preventing it.
#1 - If there's a cardboard box on the desk/table or near it when you go to see your manager, you're laid off.
#2 - You've already "liberated" tons of confidential corporate information, right? (Kidding, though I'll be honest and say I do still have my PST files from previous companies, but that's more for contact/reference than anything else)
#3 - Collect your possessions and leave peacefully.  
Life goes on.  Take a few days off.  Go fishing, do a hobby, etc.  Then start putting out resumes.  It took me 4 years after getting laid off from my first job to get back into the field.  In the meantime I did what was necessary to take care of my family.  Don't be too "proud" for anything, and just do the best you can.  Keep spitting out resumes until you find a company willing to take a chance on you, and build from there.
In the meantime, I hope you don't have to use ANY of the above advice.  But if you do... good luck.