I too have the DataVac. I love it. It does the job way quicker than the canned air, and much cheaper in the long run. Just make sure you do it outside and hold onto the fans as you blow them. I heard it makes them spin faster than they are designed to spin.
I use a Stinger vacuum, it's like a small wet/dry shop vac but light and portable. It has an attachment that makes it perfect for blowing out a PC, and much cheaper than canned air in the long run. Last I checked you can get one at Home Depot for $30.
Oakland Raiders 2013: 2-4 | THE Ohio State: 19-0 Oda break tracker 2013- 8 (3)