Pokémon Crystal/Welcome to Cherrygrove City

Introduction
Cherrygrove City is a small city on the sea. It is the first city with major facilities.

Speak to the old man near the entrance of the city named "Guide gent" to receive a basic tour of the city. At the end of the tour he leads you to his house and gives you the Map Card. This expands the Poke gear to add a map.

Optionally pay a visit to any of the houses in the city to receive friendly advice.

The Cherrygrove City Pokémart
During the first visit, the Cherrygrove City Pokémart is out of Pokéballs. You start the game with 3000 (Pokédollars / Pokémon Dollars).

Their stock is as follows:

Pokémon Center
The Pokémon Center offers free healing and PC access. The communication center is not yet available during the first visit to Cherrygrove City.

Questions

 * Expansion cards were once common in laptops and PDAs. What technological changes since the 1990s have made such systems generally obsolete? Where are mobile expansion and software cards still used?
 * Cherrygrove City is often said to be based on Nagoya, Japan. Do these cities have similarities?