I used the OneDrive code to simply set up some space that I could access from multiple computers. I also use it to backup my files so I feel more secure.
As for the Skype code, I added it to my Skype account, which I really hadn't used. I picked up a Skype handset for home use, and we now use it to make calls to family around the world. My kids also have a cell phone plan that charges for minutes used (Ting), and they can use the Skype app on their phones to make calls without using their plan's minutes.
Overall, I was pleasantly surprised that these are really useful services. I'm using them more than I expected, and I will probably keep using them once the trial ends.