I'm working on a web app that includes a file export to Dropbox and Skydrive and i wanted to add UbuntuOne, too. That means i need access to files and if i understand the U1 API docs correctly the only oauth token with access to files is full access token:

https://one.ubuntu.com/developer/account_admin/issue_tokens/cloud

But requesting a full access token requires the user to type in his username and password into my app, is that correct? Or is there another way to get a request a token with access to the user's files the same way a limited access token is requested, i.e. the user doesn't have to provide his username and password to my app?