Hi there. I am building an iPad application using Sencha Touch and I need to be able to provide a drop-down list of items to the user of the application. Now the list is very large (3000+ items) and I don't want to load a store locally with all of the data. I was thinking about implementing some sort of auto complete textfield that would allow the user to type in a few characters before I would invoke an Ajax action to load the store to display a grouped list for the user to select from. I guess I am struggling to figure out what would be the best approach to implement this 'auto complete' functionality. Should I use textfields as a filter and then convert to a list when they've typed in a few characters? Sorry this is kinda of open-ended but I was hoping to pick the hive brain for some ideas.

Would appreciate any ideas. Thanks in advance.