Thunderbird: Some may scoff at viewing web pages in Thunderbird, but it can be faster to quickly glimpse a link in a new tab than via browser launching. Thunderbird Extension WAT (WebApplicationTab) streamlines your inbox flow by making it so.
This add-on is pretty handy if you're waist-deep in emails and want to verify an emailed URL, or see if it's something worth checking out later. Instead of switching over to Firefox to view the page, WAT allows you to just right click on any URL and open it up in a new Thunderbird tab. Additionally, WAT adds a menu to Thunderbird from which you can access the about:config page quickly, as well as open up the error console or add-on utility in a new tab instead of a new window. It's no powerhouse, all-in-one solution like ThunderBrowse, but it's certain to make your life a bit easier.
WebApplicationTab is a free download, works wherever Thunderbird does. For more tips on outfitting Thunderbird, try our guide to making Thunderbird 3 an ultimate online/offline hub.
WebApplicatoinTab [Thunderbird Add-Ons]