Kaminari
A Scope & Engine based, clean & powerful paginator for Ruby webapps
...It has a simple, scope-based API and customizable, engine-based I18n-aware helpers. It's modern and sophisticated, supporting numerous ORMs, web frameworks and template engines.
Kaminari is very easy to use, with no configuration or defining anything in your models or helpers necessary. Simply bundle the gem, and your models will be ready to be paginated.