Android : Can I Stop Calling Wrong Number?

So ya, there's a phone in my HTC Hero. No surprise.

My problem is this:
I find that the easiest way to call a person is to go to the phone app and scroll through the call history displayed to find the person I wish to call. Once I see their name, I just press on it, and the call begins. Unfortunately, a friend I call often may use their house phone or cell phone when I only ever want to call their cell (Evo ). Often, the situation is that I previously talked to him on his house phone, and I'm calling him in the middle of the night (we're young; we don't sleep rational hours during the summer... or ever). Unfortunately for me, my call usually bugs his parents, and I get reprimanded...

Is there a setting that allows me to only call his cell, or do I just need to break this habit?