In that sense, although this may not be the first to come with this but NEWS RSS Ticker is another RSS feed reader that takes bit different approach by displaying lively updated RSS feeds right below your main top panel in Gnome desktop. This may not be true always but it seems to be "less" annoying than the other methods.
The app is pretty simple (heck, it's a RSS reader, not a rocket launcher :P) but it comes with an impressive options or configuration window that lets you control a lot, I mean a LOT of features such as...
*. Auto hide the ticker/bar.
*. Change height,width, etc.
*. Set different fonts.
*. Add/Remove shadows (you know, so it looks like 3D and stuff ;-) ).
*. RSS update settings (delays between each update, etc)... are very few to name.
For a better understanding of how powerfully they let you customize it, have a look at the below screenshot. It's written in GTK+ so integrates with Gnome desktop really well too. In the bar it displays the "meta descriptions" of the Feeds and their title so you can easily "choose" which to read or which not to, etc.
So if you have installed Ubuntu 11.04 Natty Narwhal or 10.10/10.04, etc you can install RSS Ticker using the developer's personal PPA page or can simply get the ".deb" package from here and double click and follow the instructions on your screen.