new helmet

They're talking about the Sigourney Weaver's Alien head looking helmets.
Once you get into those, get the one that touches your back all the way down and that's the most aero for you. How you hold your head will be the deciding factor in it, not the helmet itself.

So other than those alien helmets (remember PeeWee Herman's bike dream?), it doesn't really matter for normal bike helmets?  Lance's bike helmet during Tour de France is just any old mail-order helmet?

I need a new helmet and I will not be ordering one of those alien ones, I want one with good ventilation, but should I worry about the aerodynamics of it all?

I like the looks and benefits of the new Lazer helmet advertised in the latest Triathlete mag.  I am about due for a new helmet and am leaning towards it.  I just need to know what it costs.

As with all things aero, it has to do with YOUR position with the gear and your speed. Generally, ventilation = more holes and more holes = less aerodynamic. While there are some folks who benefit a fair bit from aerodynamic gear, you really need to be up there in terms of your average speed to make the most of it.

If it's hot where you ride and you're planning to use this helmet for racing and training, just get whatever helmet will keep you cool and fits properly. Even if you had an aero (alien) helmet, you wouldn't train in it (most likely)

You have 2 different styles of helmets...aero and "standard". I believe the "standard" bike helmets as far as aerodynamics are all basically the same. The more expensive "standard" helmets simply have better circulation and may offer a more comfortable fit. But comparing a cheap $30 standard bike helmet versus the more expensive $240 standard bike helmet, as far as safety and aerodynamics are concerned, the difference is slim to none.

But as the poster above said, the "aero" helmets you read about are the ones that look alien like.

Thanks all!  This is exactly what I needed to know.  For my level of fitness and skill, any old helmet will do.  Price will be a driving factor.  Performance is second factor and color/fashion is third. 

My helmet is way too old. Helmets are good for only a few years, and mine is about 8 years old.