We have been using bottles in our house for the last 8 1/2 years. I usually get about an 11 month break between kids, and even shorter between Brennen and Preston! Since the break is never that long, I never pack them away. They've always been given their own cabinet in the kitchen. Just recently we ran out of formula. Being the cheap parents we are, we opted to go ahead and switch Ella to whole milk 2 weeks early. I know that there are those who probably think we're terrible and don't care about our child's health, but oh well.
The above picture shows the bottles we've amassed just since Maddox was born. (Caden was a Playtex disposable bottle baby.) I set them out to take a picture for Craigslist and was a little sad that we'd never have them in our house again. But I was also happy that I gained a whole cabinet back, which was quickly settled by sippy cups! (BTW, bottles sell VERY quickly on Craigslist!)
Anyway, we have always done a cold turkey switch to sippy cups with our kids, and never had a single issue. Ella was no different. She loved the milk and has never looked back. Here's a few pictures of that first cup of milk.
"Why is Dad taking a picture of me drinking my milk? He's so weird!"
"Guess if I'm going to be photographed, might as well smile!"