Whilst you are correct that the main UI does not have a preferences button, I was invited to enter my Twitter credentials on initial startup.
I was also able to later re-use the Preferences dialog by right-clicking gTwitter's notification area icon and selecting "Preferences". Whilst it would be nice if the UI was a bit more transparent about available options, I don't think this qualifies as a GRAVE package problem? -- Matthew Exley hen...@guided-naafi.org