Hide contacts with only email address
You have not mentioned your Android version, if it is Android 4.0+, I fear you cannot do this. There's no option to show contacts with phone numbers only in People app that is included in 4.0+. 

If you are on GingerBread or earlier versions, you have a setting something like this: 

Contacts app - &gt; Menu -&gt; Display Options -&gt; Only contacts with phone numbers


I am talking about stock Android apps, your manufacturer / ROM builder may have a tweak depending on what ROM are you running. I don't see a chance, but still a possibility.

See this similar question.