I may be the last person on earth to learn this, but hey, these are my lessons and I learned it… from Kat.
If you want to delete something in the search or web (or any) field on the iPhone, just hold the delete button down. You do not, after all, have to hit delete-delete-delete until you drive the person sitting next to you crazy.
When you do this, it deletes slowly and then very quickly, deleting entire phrases at a time.
Who knew? Did you?