Take your to-do list everywhere you go. Just go to mail.google.com/tasks from your mobile browser!!
It seems to let you choose the task-list; you can quick add tasks to that list, you can clear completed tasks, and you can add up to five in one go... it really seems like a great way forward, but in my view, it's a sorry replacement for the VERY useful m.google.com/notebook feature that they've done away with, but at least with this one you can add tasks. I just wonder if you can SHARE task sheets, because that would be the bomb (google bomb?) :)