If you are a Firefox power user like I am, then you probably have dozens of tabs open all the time. After trying a number of different options, I've finally settled on using multiple rows of tabs as the best option. To set this option, you must have the Tab Mix Plus extension installed. Assuming you do, open up the Tab Mix Plus options dialog via the Tools menu. Choose the Display tab/icon on the top, and then make sure you have the Tab Bar tab selected. Change the option for "When tabs don't fit width" to "Multi-row", and then check out the multiple-row goodness.

Of course I don't usually browse at 600x370...