Silly question

Yes, they do exist, but they are not very common. I do remember seeing them in a few places, in the UK and other countries, but I cannot recall where.
I don't think they are very fussy what coins you put in, as the machine is squishing them. You have to put in an extra real coin as well to pay, they want to make a profit.
I think a Scotsman would object to destroying a 20p coin, 1p or 2p only :-)

For a small mementoes and reminders, how about keeping transport tickets. Train ticket, London tube, Paris métro ticket etc.

I LOVE THOSE TOO! So this question intrigued me so much I googled to find out what those machines/coins are called - and found this!

http://www.pennycollector.com/Locations.aspx?area=92

The coins are called "elongated coins," and the link above is to a site that lists locations in the UK. It's actually been updated as recently as this month, so it's fresh. Looks like a penny is fairly standard, but some machines take other coins.

Happy hunting for the machines - and have a great time!

Chris F,
In the US, the penny is destroyed and becomes the souvenir. The $0.50 is the fee.

I see them in some of the tourist areas. It is very clear on the front of the machine the coins to be inserted. If you have a hand full of coins I am sure you will have the correct coins.

I keep these squished pennies in the pockets of various jackets, though not usually the jackets I have on when I do the squishing. I'm especially fond of the ones with female saints.
The machines usually have more than one design to choose from, and I find that if you turn the crank so that you're not quite right-on-the-money you can generate interesting double exposures, too.

Yeah, these things are very popular in the States. You're likely to find them at tourist attractions (i.e., here in the west coast, Santa Monica pier in LA, Fisherman's Wharf in SF, Old Town Sacramento). I agree with keeping transit tickets as a good souvenir. I've saved many of mine, from all over the world, along with hotel business cards, menus, and other such things. They're basically free souvenirs, and unlike some more expensive things like locally made handcrafts etc., these items aren't likely to be available for purchase anywhere online.

When we were in the south of France, there were machines that gave our a fake euro bill with a picture of the attraction you were visiting...we got one in Arles and one in Nimes and one somewhere else. Not as small as the squished pennies tho...

I saw several of these machines on my recent trip to the UK, but unfortunately, I don't remember what coins they took. I do think it cost more than 20p, though - maybe as much as £1?

However, you will quickly accumulate a large variety of coins, whether you want to or not, so don't worry. These machines are often near gift shops, so you can always get change there.

I do remember one of these machines in the Dublin airport, which would have been a problem if I wanted to use it. Since I was going from the US to the UK and back, and merely connecting in Dublin but not stopping in Ireland, I had USD coins and GBP coins, but not EUR coins! One way I could have gotten them was to buy something from the snack stand with cash; the vendors will take foreign notes, but give you change in EUR coins.

I have collected those for years...I remember I was so excited to find one on the Tower Bridge! The Penny Collector site is a great resource

From the list linked above, I can confirm seeing them at Portsmouth Naval Museum and Bletchley Park last month.

The Penny Collector website above is fascinating. Looking at the sights I visited, I see there were MANY machines I would have encountered.

We have a couple of these from our trips to London, Paris & Italy. Tell your wife its a fun question not silly.