Firefox only (Win/Mac/Linux): Firefox extension Tab Utilities can customise just about any tab-related setting you can think of, from loading tabs from a clipboard URL to locking or faviconising a tab with a Shift+Click.
Once you've installed the extension, you'll notice the only real annoyance — the default Appearance setting is to outline the selected tab in blue, but you can easily turn that off in the Tools -> Tab Utilities Options ->Appearance section.
After you've made that change, you can get started customising pretty much anything you can imagine, from what happens if you left, right, middle or double-click on a tab, to whether a tab is re-focused when you open the same link again. It's a powerful extension in a fairly small package, and a good alternative to the popular, but larger, Tab Mix Plus extension. Tab Utilities is a free download, works anywhere Firefox does.
Tab Utilities [Mozilla Add-ons]