Note that you didn't have a tab open, but IE7's tab bar is too huge and doesn't go away. Office 2003 and macfox (I have all the navigation stuff, address bar, and menus on one row with my bookmarks under that) are good looking, small themes that don't abuse the eyes (the "shift" themes are painful). I like the customization abilities of FF, I can put my buttons where I want them, get themes, and have extensions that can do everything but clean my room. I use NoScript and AdBlock Plus, no ads. Ever (unless I allow the site and the ads are from their site, then it depends).
I stopped IE7 from installing on my computer, so I still have IE6. Yes tabs are nice, but only when implemented in a logical way, I must use my middle clicker of death on tabs, and the middle clicker of life to open links in a new tab. Though I must admit, FF is a resource monster, not a good thing for my computer, but its better than having 10 windows of IE6 open.
I'm going to a new high school this year (its literally new, just opened, thats why I went to a different one last year), and I really hope portable FF works on their computers, but I don't have any computer classes, so it'll be hard to find out.