So, here's the first in the series: Creating barcodes.
Wolfram|Alpha is an awesome tool. It can actually code any kind of data into barcodes. Easily put, if you type:
Replacing the 'anything'
So? Not such a great pastime? You can actually put it to use. You can use it to leave messages for someone. You can snap a screenshot of the barcode from the page, and save it somewhere. The other person can decode it using a barcode scanner in a phone. Android phones have it, and you can download free barcode scanning apps for almost any kind of phone. It needs to have a camera, duh! Even Symbian users aren't left out here. Try the free UpCode and Kaywa Reader if you are stuck on Symbian like me.
Probably you'll find more different uses to put this barcode creation to use. Let me know in the comments! Try scanning this barcode: