For Christmas last year, I offered myself an iPod, and I found that the interface, made for big fingers on a small screen, is surprisingly friendly and intuitive. OK, granted, some things are harder to find than other (like how to kill or group apps), but the overall experience is agreeable. You don’t feel the thing as a new device that breaks your work-flow, because you can’t have a work-flow on this thing.
Ubuntu 11.04 came out in April and it offered—well, kind of imposed, actually—their Unity desktop environment, and it does break your work-flow. Not because it is clunky (because it is), but because it does not offer ways of doing what you’re used to on a workstation, it tries to replace what you’ve always done by something “revolutionary.”