Go to your nearest large metropolitan (outside the one you live in of course if you do) and spend a weekend there.
If you do live in New England, $500 can buy you an okay weekend in NYC. I think I spent $10 -$15 for a bus ride from Boston to NY a few years back.
Next go onto airbnb.com and find a cheap room for the weekend.
Then it all comes down to your interests on what you do there.