With some strategic caching, TodoCue processing times are down from the 200ms range to less than 1ms for many (repeat) requests. New features include embeddeding in iGoogle by using this gadget, cancelling editing with Esc, and saving by clicking away from an item. The app is now translated into Español, Français, Slovensky, and Svenska.
I'm looking forward to seeing what snazzy styles people customize their TodoCue with (via the custom CSS field under Account). Send them to me and I'll make them options for all users. As a side note, I plan to release the code under a FOSS license; stay tuned.