You may not like these options, but the following techniques have been proven to put $100 in your pocket over and over again.
It would be best to make your next $100 on something legit, but for those looking to squeeze an extra few dollars out of almost nowhere…
1) Dumpster dive for bottles
At 5 cents a pop, you only need 2000 empty beers to reach $100.
2) Theft from loved ones
One of the easiest jobs around. Just don’t get caught.
3) Cash in as an independent rock musician
Find 3 pals, practice for months, record an LP, tour 25 cities, and hope to sell 45 CDs.
4) Circular math
Lend yourself $120 from your long-term savings, pay yourself back a down-payment of $20, and record the tranaction on a napkin of your choice, take another shot of JD, and be sure to discard the napkin as soon as possible.
5) Prostitution
Find a local bar where people hang out that are 20 - 30 years older than you. If you can’t walk out with $100, you don’t know how to make $100.
Or, now there’s online prostitution too: Safe for work article from Alternet
6) “Protection” money from neighborhood children
$5 a week for you to NOT beat up a local kid x 20 kids = $100 per week. Recurring income potential.
7) Palladium rustling
Platinum & palladium are good for catalytic converters. Find 5 large vehicles (preferably SUVs - cars that need more pollution control carry more of the precious metal), cut out the catalytic converter, and laugh your way to $100.
Work 7.69 hours at an Alberta McDonalds
That’s right - the job market is so hot in Canada that brand new burger-flippers, fry cookers, and drive-thru window operators are making $13 an hour. Starting wage. Actually, this might be the best option from this entire list…
9) Think up a good joke
Send your joke to Readers Digest and hope for the best.
http://www.rd.com/submitjoke.do
10) Piracy
Find a deserted highway or spot on the open seas, practice your accent, and watch the money happen.
11) Set up a mobile pay toilet
Dirty work, but set up shop next to a concert, ball game, or outdoor event, advertise as having “the cleanest seat in town”, and charge $5 for 5 minutes. Make $100 in less than an afternoon.
12) Buy gold
Throw $100 USD at gold, wait 30 days, then trade your gold back for USD. WIth today’s rate of currency colapse, making a spare $100 is almost guaranteed.
13) Bet against the Toronto Maple Leafs
Always a safe bet.
14) Set up a fake online business
Set up a system for people to pay you money for something you may or may not end up doing. Best if done if you do not live in a country with fraud charges or the rule of law.
15) Invest $2857.14 at 3.5% interest.
Thanks to Fedhead Ben, compound interest now almost pays for your banking transaction fees.
16) Clean out the vacuums at a local car wash
Most automotive vacuum cleaners hold at least $5 in change by the end of an average day. I even found a $20 in a vacuum one time. You’ll have to rinse off your findings, but this is some of the easiest $100 around.
Bonus #17) Google “$100 Prize”
There are lots of contests & competitions for a $100 prize. Who knows, you just might win something. But personally, I’d stick to something more tried and true. 
Double Bonus –> Okay, fine, this list is full of dumb ideas… But if you look & see what’s behind the colorful box below, you’ll help this dude get closer to his $100 