Tabbed browsing is great, constantly swtiching between tabs is not. If you need to view two or more tabs at the same time, check out the Split Browser add-on. Click on any tab, then select "Split" from your browser menu. You can choose to split left, right, above or below, and tile all current tabs vertically or horizontally. This can be extremely useful when you need to reference while you're writing, editing or updating a Web page, or want to browse a few sites simultaneously.
The split tab is fairly independent. It can be refreshed by clicking on the top bar and you can navigate to other pages through the drop-down navigation bar. One point of interest: some Web pages will automatically refresh when you split the tab, so be careful if you're working on something important. You might want to save your work before splitting the tab.