FVD Speed Dial is one of the best Firefox add-ons I have been using. I used to build my own customized start pages in HTML until I came across this one. I know this is just an add-on, but you can do a lot with it specially if you have to present in front of your class, a professional development group or at a conference.
This add-on was developed by Pavel Shcherbakov, and it currently has over 59,000 users worldwide for the Firefox version alone. It is compatible with Chrome, and it works just fine on Mac computers running Firefox or Chrome, as well. The add-on is loaded lots of options to customize the look and feel of your start up page allowing you to synchronize your settings across computers, organize your bookmarks, add custom backgrounds, custom dials, create and organize groups of tiles, and your most visited websites. You can get the add-on here. http://bit.ly/PjPIas I have also created a short video to demonstrate some of the customization features.