Do you use canned air to clean your computer or other electronics? Compressed air can be a Handy tool, but it can also be a bit pricey. Where do you find the best deals on this product? I have found that it is cheaper to buy more than one can at a time. A three pack (at Walmart) ends up costing less per can. Not a lot less but it is a bit of a price break. Do you have a good source?