Re: Don't do that!
The SunRays were fantastic for that. I was working for Sun at the time, and they were everywhere in the vast Sun facility I was working at. Getting from one side of the facility to the other was about a 15 minute walk. As part of the job I often had to go all over the facility, and being able to just walk around with my ID card and slot it into whichever SunRay was closest meant no dragging a laptop about, and laptops weren't common at the time, most organisations used desktops. Meetings were great too, the team just slotted their ID into the SunRay in the meeting room and there were the materials they wanted to demo.
The downside was when you forgot to pull your ID card out of the SunRay and walked away, most typically happened when you left your ID card as far away as possible from where you next needed it, usually back at my desk at one far side of the facility. Bonus points if the SunRay in question was behind an ID card secured door (we had them in the comms and server rooms), so in addition to the long walk you needed to beg a colleagues ID card (who then couldn't work on a SunRay until you got back)