Simple example of how to use the named\_scope feature:
```ruby
class Feed < ActiveRecord::Base
named_scope :active, :conditions => "(active = 1)"
named_scope :stale, :conditions => ["last_updated > ?", 30.minutes.ago.to_s(:db)]
```
Usage:
```ruby
Feed.active # return the active feeds
```
Chaining is also possible:
```ruby
Feed.active.stale # return the feeds that need to be updated
```