You can find Penny Smashers in just about every tourist attraction (including rest areas). For between 51 cents and a $1.01 you have an instant souvenir.
|The Philadelphia Visitor's Center|
We have also found these great Penny Passport books to keep all their pennies safe and sound.
I suppose that as the designs retire, they may have a few collectors items on their hands, but really it's just for the fun of having a collection, and an easy and inexpensive souvenir.
And of course, you can find the Penny Smasher Waymarking Group is actively indexing the locations of these machines, if you want to find a penny smasher, log your visit or index one yourself!