Hi there, hope I can help...
app doesn't seem to have an uploader.So, you have to visit the mobile Facebook
site on your internet browser. If the photo you'd like to upload as your Facebook
profile picture is in one of your Facebook
albums, you should find a link underneath the photo that says "make profile picture." Click on that. Or, if you'd like to upload a photo, click on the photo icon underneath your profile picture and upload a photo from there, then choose "make profile picture" again.
Unfortunately, there's no word yet on when Facebook
will allow you to do the same on their app.
Hope this helps,
— modified on Sep 27, 2011, 2:39:28 PM