##Javascript, 90

    for(r=Math.random,s="",i=5;i--;)s+="bcdfghjklmnpqrstvwxz"[~~(20*r())]+"aeiouy"[~~(6*r())];

If run from the console, output is shown. Explicit display would add `alert(s)` at 8 chars, still shorter than the other JS solutions.