With Fluid you can give your favorite web apps their own contained Safari-powered space on OS X. Once wrapped, the applications get their own icon, their own place in the Dock, and their own lifeline, so crashing your general purpose browser won’t take down your Fluid apps.
It’s neat and free. Check it out.
(If you’re not on OS X, Prism does something similar for Windows and Linux powered by the Mozilla engine).
Update: Here are high res logos for Basecamp, Backpack, Campfire and Highrise to use with Fluid. (Click to download).