Here's the problem: This week it occurred to me that my AppleCare subscription on my MacBook air was perhaps about to run out. I needed to go and look up the exact date that I purchased my Macbook Air so I could track this back. After doing some digging in my email folders I located the original PDF of the receipt from the purchase. But that took too long.
Here is the solution: I created a secure note in 1Password where I recorded the serial number of my Macbook Air, the model number and purchase date. I created PDF's of both the receipt and the webpage that gave me the details on the expiration of the AppleCare plan (which turned out to be next year). Now I have this information securely stored at my fingertips. Because I use 1Password on both my mac and iOS devices I'm able to get to this information wherever I go. I'm now creating similar notes for all of my Apple purchases and other products that have warrantees that expire. It occurred to me that this could have been done in Evernote as well however I found some elegance that it's secure in the 1Password app behind a very powerful main password.
1Password is made by Agilebits and can be found at https://agilebits.com/onepassword.