OK here are some major applications:
1. Scraping lists for GSA and etc.
2. Scraping expired WEB 2.0s and etc.
3. Checking url stats(PR, DA, PA, Indexed, Has Link.) etc etc.
4. Scraping E-mails from pages
5. Scraping Images from Google(perfect for instagram/pinterest)
6. Linkbuilding via blog comments
hell I can't keep going, there's no end to it