I work for Cisco. A lot of their higher-end, next generation collaboration devices (which basically means video/voice devices, in various form-factors) run, or are going to run, Android. We don't really re-skin the operating system itself like a lot of vendors do (Sense, Touchwiz, etc) but we do heavily customize a lot of the core Android apps to include our branding, visual style, and features.
I personally have been working primarily on customizing the Email and Calendar apps, with some dabbling here and there in the Lockscreen, Launcher, system UI, Settings, Browser, etc. IF you work in an office that orders new Cisco desktop gear, and you were to compare the Email and Calendar apps to their standard Android counterparts, you'd find a lot of visual differences, and I did the vast majority of that. Also things like Email sorting, a large portion of Calendar's WebEx integration, blah blah blah.
Anyway, you don't care, so I'm sorry for going on. The best visual demonstration I can give is in the video below. It's short and entertaining enough to watch, more or less. Not a bad commercial. If you pay attention around the 30 second mark, they give a super-short shout-out to Email and Calendar. See how they look weird? Yeah. I did that.
Thanks for asking.