I am a relatively new Android user, and I love my Android RTM app. I am also a very forgetful shopper. I either find myself a) calling my wife to continually update my shopping list, and b) Remind myself that I need to buy more "X" when I am at store "Y" only to forget about it until I've returned from store "Y" without it. But RTM has given me a new way to manage these tasks, and make sure that I always have the correct list in front of me, here is how I do it:

1. I set up locations on the RTM web site for the stores I go to most often (i.e. @market, @warehouse, etc).

2. In the RTM android app, I turn on the option to notify me when I am close to a location where I have tasks due.

3. I then add tasks with that location, I can also forward my shopping list to my RTM list import address and make sure I append @market to each entry. It also helps to add a due date so that the task is either due or overdue at your next visit.

4. When I arrive to the store, RTM gives me a popup alert indicating that I have tasks due at this location - clicking through gives me my shopping list for that store, and I use it to remember the things that I need.