Hiring manager perspective: I called someone this morning who wanted a job, and he wasn't there. So I got his voicemail, and there was no name on the voicemail; it was a generic recording provided by the phone company which read out his phone number. How do you think I felt about leaving a message for him, not knowing if it was even the correct number?

If you're looking for a job, put a message on your voicemail which says what your name is, and says that you're sorry you missed my call and will call me back. Then, keep on top of your messages to make sure you don't get into "mailbox full".