Power and Cooling are  the big challenges of datacenter operators. We are beggining the second phase of our datacenter expansion at iWeb and cooling has been part of our most discussed preocupations.  We have also been preoccupied with the noise that can be associated with the cooling equipments inside and outside the datacenter. I am waiting for new cooling solutions like  HP seeks smarter data-center cooling | CNET News.com to come out and hope new interesting cooling alternatives will be available soon.