Lately I have been trying out Konqueror along with my normal use of Mozilla Suite. Being accustomed to Mozilla it is a bit difficult to get myself at speed with Konqueror's shortcuts. But setting that aside, I found a neat feature in Konqueror: Split Pane.
One can split a pane either horizontally(Ctrl+Shift+T) or vertically(Ctrl+Shift+L). These individual panes can be further split up and most of the time this further splitting makes this feature useless! However, for a person who is working on two webpages and wants to compare the new one with the original, this feature will come in very handy.
Above is a thumbnail showing two webpages side-by-side. I was comparing mozilla.org's main page to itself about an year ago. Wow! That is a huge change in design ;) I just can't wait to get KDE 3.4 on my Debian box. KHTML(Konqueror rendering engine) is said to be complete CSS2.1 complaint.