coffee is the only thing i've ever really been addicted to. late last year i started to develop stomach problems so i went cold turkey. i felt really good, my energy levels smoothed out (didn't peak and crash as much). my problem was i just wasn't eating enough food.

however, i find it nearly impossible to avoid in an office setting...so once in a while i get a small cup from somewhere and drink it only if i have a snack or meal. that seems to work for me.