What is the cheapest, easiest, and/or quickest way to get into a 1990 Bonneville LE? I don't want to get into the story about who locked them in, or where it is, or why I don't have an extra set of keys available. It'* cold, I'm broke, and I really need to get into my car. Any help will be greatly appreciated.

***EDIT***

A friend paid for a locksmith. I'm good. I haven't seen one done that way. He had a pneumatic bag that slipped between the door and pillar. It pried open the door just enough to fit in a bar that very easily tripped the lock button.
Something I noticed, he never asked me for ID or proof of ownership.

Search through the archives for threads on the rear door lock. The lock commonly reezes up. One post shows exactly where to insert a slim jim type tool to unlock the back door.

You could probably get away with a coat hanger bent appropriately.

You might also want to try threading a coat hanger around the door and try to hit the unlock button if you have power locks. If you have manual locks with the smooth buttons, you're stuck with the slimjim

Carry a spare door key in your wallet.

this would be a good time for the plastic key :o

For me the "cheapest, easiest, and quickest way" to get into my car(*) was the Mobil Auto Club. For about 60 bucks a year it has saved from some really "stupid" situations such as locking my keys in the car, whether I was in Newport, Rhode Island or Miami, Florida, or even Parsippany, New Jersey. It doesn't take me much to get distracted (what was that?) and the chime thingy-dingy doesn't always work in the ignition. I have also used their services for such things as getting towed to a repair facility to install a Starter when I was in Virginia. So, for some of us, I would recommend an Auto Club of some sort for those days that don't go jusssst quite right.

I've had good luck with using a thick wire coat hanger, fasioning it into a slimjim type shape. use it the same as a slimjim, popped open three cars in under 10 seconds each.

But you're already in your car so I guess this won't help

That does help a lot, actually.
I tried the coat hanger trick but I felt like I was doing more harm than good. I gouged my weather stripping pretty hard.
No matter how careful I am, I can't control what my passengers do when I leave my vehicle. I went into a store, left my keys in with the radio playing for my friend. He decides he wants something and dutifully locks my car as he gets out. I appreciate that he was looking out for my car, but... you know the rest.
I only got one set of keys with this car and haven't found a shop capable of duplicating them successfully. They look very worn. I've had them cut duplicates but they don't work. I didn't receive the key # or any of that cool stuff new car owners get.
Now I'm off to research the slim Jim trick and weather stripping.

Thanks everybody.

I had a worn key for one of my cars, (very worn)the Chevy Citation. I had the dealer cut my keys. They did an awesome job, and I will never have keys cut anywheres else but a dealer. I like GM OE keys, the look and authentic feeling.

Did you try getting it cut at the dealer?

good point. All you need is the key code and the dealer can cut you one.
Some may even look it up for you.

Whenever I go to the dealer, I swear they start rubbing their hands together and laughing maniacally, "Moo Ha HA Haaah"