Send a project/list with all items included in one single sms
Be able to manually send project/lists, like ex. shopping list, with all items to your phone via sms.
I know there are workarounds already, by using accessing your lists with your smartphone or internet on your phone (if possible), but not all phones are capable or you may not want to use extra expenses to retrieve the lists.
Setting up reminders via sms is possible, but as far as i understand its one sms per item (correct me if i am wrong), which will end up with a lot of sms'es for your "shopping list". Also you will avoid to change or add a date to the items you need send to your phone, with a solution above.
All and on, it would certainly be more convenient. And if you happens to make it, it would be nice if it was possible to send at least a couple of such sms pr month for regular users :)