I know that years ago one could go to the airport and wait for a flight that had availability is buy a seat at the last minute and get a very cheap deal... is that possible still? I saw that you can fly standby only if you already have a ticket, but I'm wondering if that last minute is still possible.

Yes, "standby" still exists. But its a much bigger gamble than it was just a few years ago.

Flights are routinely overbooked now and airlines have cut back this year on their total number of flights by 4% overall, both of which leaves less seats for you to hopefully get a discount for. Plus, standby seats, for all the risk involved, don't give you the discount that they used to - 10% to 30% discount is common, which on anything less than a $500 ticket hardly covers the time, parking costs and hassle involved, especially if you don't end up getting on a plane.

If you truly are flexible on flight times or departure days, you can still get a deal with standby. Just understand that 10 to 15 years ago standby usually meant you would get on the plane. Nowadays, not so much.