What kinda cool stuff can a palm pilot do?

What kinda cool stuff can a palm pilot do? Also, are there monthly fees involved? and how much do they cost around $100?

Very little these days - there’s no monthly fee but palm pilots fell out of use around 10 years ago - you’ll only really find them in places like warehouses and supermarkets where they are used with barcode scanners to perform specialised tasks. An old one on eBay would be less than $50, but for a more modernised unit in a scanner they are a lot more expensive.