Android How to set new default user for Android Marketplace I have a Sprint Samsung Captivate phone, and I am somewhat sharing it with co-worker.  Problem is that every time I want to download an app free or otherwise, her username comes up and prompts for password.  I would like to add own email and download under that without removing her account.  Much easier said than done.  I cannot seem to get her logged out and a new prompt for username and password where I could enter my user name.  This is a much tougher problem than I ever imagined.
Unfortunately you can't do this.  You would need to entirely remove your account (the primary phone account) from the phone and add hers as the primary account, which would perform a factory reset on the phone.  Hopefully future versions of the Android OS will support multiple users, especially the tablet versions, but currently it does not.