Roller Skates are a new item given to you when you reach Santalune City. They provide an alternative method of transport to running and the bike, but there are many unique factors to it. When you use the Circle Pad on the Nintendo 3DS, the Roller Skates activate. They allow you to go off of the standard grid movement that is done with the D-Pad and give you greater freedom.
Dotted around the region, there are various rails. These can be jumped upon when you have the roller skates out and give you access to a variety of previously unaccessible areas which typically have items. Some of these rails have dips that will knock you off if you are not going fast enough.
There are also five tricks to be obtained in the game, the last of which can only be obtained if you have the previous four.