OI Shopping List: Cloud sync (eg Dropbox)
Add a cloud sync option, and make the files easily editable in some desktop app such as excel. This way you could share a list between phones.
Tassilo Horn commented
That would be awesome, and basically implement the synchronization thingy feature request with more than 100 votes with a very simple approach. Basically, customizing the location where shopping lists get stored should be the only thing required.