MoStacks is a free program for managing data (a "database") running on Symbian/UIQ3 phones like the SonyEricsson P990i and P1i models. It was inspired by Apple's famous HyperCard application and offers a wide array of features including picture support, WikiText and script programming. At the moment (end of 2008) it seems to be only general UIQ3 database program available that addresses end users, and it might be one of the most sophisticated freewares ever released for UIQ3.
You find more about this program here.