I am an overly enthusiastic Fitbit fan. I've had a Fitbit for about four years now. I use to sync through my laptop computer all the time before I had a smart phone. Synching through a phone is a little more convenient, but it is not necessary. I just posted a personal review of the Fitbit One on my blog:
http://slysamgettingfit.blogspot.com...bitreview.html , I hope it isn't spamming to post as I do have an Amazon Affiliates link at the bottom of the post. The link is quite easily ignored though. PS--I just noticed the Burgandy One (which is what I have) is currently priced $10 less than I paid on Amazon, not to enable. Their prices are kind of quirky.
Oh the difference between the One and Zip... I don't have a Zip but the One has a rechargeable battery. I charge mine about once a week while in the shower. The Zip's battery is replaceable. The One tracks flights of stairs/hills and has a sleep/activity timer and the Zip doesn't have those features. I don't know whether the Zips display lights up or not.