Listacular is a streamlined list and note app with Dropbox sync (txt). With Listacular, you can rapidly create to-do's, outline projects, or take notes. Since it syncs with Dropbox, you can pick up and work on your lists from anywhere. The coolest part is that you can share lists with others and collaborate on lists (imagine a shared grocery list with your friend/partner).

I'd appreciate your thoughts on this. Lists use a markdown-like format for easy list creation and editing. You can edit lists from anywhere, and the app uses a 3-way merge strategy to intelligently bind changes from multiple sources.