Bumpr is a handy, beautiful Mac app that lets you choose where to open links. Anytime you click on a web link, a compact, elegant menu pops up right in place and let you choose which browser to open that link with. Bumpr also works with mail links.
Bumpr is particularly effective if you use more than one browser to run separate Google accounts, for cross-browser testing, to keep certain kinds of browsing activities restricted to certain browsers, and more. Its email handling is great if you use separate email clients for different email accounts.