reduce memory usage of "Internet" and "contacts"
Assuming by "Internet" it means the default browser, then you should be able to go to Browser Settings to delete History and other cached data (press Menu button on the Browser, then select More, then Settings).

As for Contacts, if your address book are synced to your Gmail Address Book, you can Clear Data in the Manage Applications. After a short while, the Contact app will resync to Gmail Address Book hopefully without the Facebook contacts.