My Site is a personal site that gives you a central location to manage and store your documents, content, links, and contacts. My Site serves as a point of contact for other users in your organization to find information about you and your skills and interests. Content providers can use My Site as a method of customizing the information they present to users.
I've got templates for printing on the different types of sign paper, order guides for TIPP, manuals for different equipment (to look up part numbers). It's nice to have one page to go to for all of my needs, rather than being forced to do it only from a single computer.
All TLs and ETLs were instructed to use it some time last year when target halted to ability to use jump drives on the computers, however I do believe that the PCs in the HR office and the AP office will still allow use of the jump drives.
Oops I am dumb, Corporate has an iteration of MySite that they use as an "About Me" page for many of their employees. The stores version of My Site is supposed to replace using local storage to keep documents like Coachings and CAs, reviews, statuses, etc as others have suggested.