When multiple tabs in your browser are not enough, try splitting your browsing area instead.  Split Browser, an add-on for Firefox, divides up the context area of the browser in many ways.  Want an over the top example?

That might be a little extreme, but it does help to point out that this extension will let you split your browser up however you see fit to do so.

Here are the various ways you can split things up:

• Choose the “Split Browser to” menu in the context menu.
• Choose the “Load in Split Browser” menu in the context menu on link.
• Click popup-button on top/bottom/left/right edges of the content area.
• Drop links, bookmarks, tabs, etc. to popup-button on top/bottom/left/right edges of the content area while dragging.

To close split browser frames, hit the close button (for that frame) or “File” > “Close All Split Browser” closes all of them at once.  Another neat feature is that the status of the split browsing window saves, so it will automatically restore your splicing of the browser next time you start Firefox.

Split Browser is a terrific add-on if you are looking for a unique way to browse multiple web pages at once.