My mom is morally against the self-check out lanes in many stores now because she feels it is taking a job away from a real person. Yea, yea, that may be true (although there is always someone there monitoring). But I LOVE them!
I think it taps into my childhood love of playing grocery store. Beep....beep...I really love scanning the items. Even more, growing up with a UPS father, I love bagging the groceries. I love the control too and not having to chat with the checker when I'm in a hurry (I usually like chatting with the checkers, especially the ones I've come to know over the years).
Besides drive-thru coffee and pay-at-the-pump gas stations, this is one of the best inventions of the past 5 years.