Layout question (Twitter-client-like app)

Hello,
I am new so hi to all of you :)

I want to create a client for a Twitter like service (although it's not limited to 140 characters).
I want to have a custom widget that would contain all the elements responsible to display a "tweet". The crucial part is the label that would display the message. I need the widget to always adjust so the whole message is visible. Moreover, I need to have those widgets layed out one under another and if not all of them fit in the window I need to have a scrollbar.

Humble example (let's say its my application window) of course the labels won't be the same height:
http://img.skitch.com/20100109-px3wd...j3mjwn5eyb.jpg

I am battling whole day with it and can't get it totally right.
Any suggestions ?

Thanks.