Based on some inspired & most welcomed feedback, I've added some vertical rythm to the grid. I'm amazed by how much better it looks now.
Useful resources about vertical rythm
I followed some advice and read (with a lot more attention this time) an article written by Wilson Miner at A List Apart entitled: Setting Type on the Web to a Baseline Grid.
I would also recommend reading the The Elements of Typographic Style Applied to the Web. The focus is on typography on the web, and the chapters are full of tips and best practices. A must read
While things look all lined-up on Safari 3.1 on OS X, I have no clue if it looks even decent on other browsers. I don't have enough time yet to make them look better in other browsers, even though Firefox is next on the list.