Shopping Cart is a great free app released by crackwhore of XDA that lets you keep a running shopping list. It just received a major upgrade:
QVGA resolution support!
Functionality to remove an entry altogether.
Tabbed cart lists to separate shopping carts for different stores.
Custom/enhanced save/open/browse dialogs. Default Windows Mobile ones are awful.
New configuration utility to change application settings, rather than modifying the registry.
Numerous new user-configurable settings and options via configuration utility.
Saving a list now retains the marked/unmarked status of a list when it is saved and re-imported.
New menu item(s) to check / uncheck all items in the cart list at once.
This release will work for QVGA (like the Tilt) and WVGA (HD, Diamond2 and TP2). The download is available here, as is a donation link to support his work.