With Safari 4, Apple shrank the toolbar’s Refresh button and moved it to the end of the address bar, close to other easy-to-hit targets. If you’ve missed the old button, you’re in luck: thanks to Safari 5 extensions, you can bring it back.
Start by enabling Safari’s developer mode. Go to Safari > Preferences > Advanced, and then select Show Develop Menu In Menu Bar.
From the new Develop menu, select Enable Extensions. Now go to www.macworld.com/6307 and download John Siracusa’s Safari Reload Button extension. Double-click the downloaded file to install it. Now Control-click on the Safari toolbar (or go to the View menu) and choose Customize Toolbar. Add the new Reload Page button wherever you want it on the toolbar.