If you are using tabbed browsing in Safari you can turn a folder of bookmarks into a tab set. There's a little checkmark (auto-tab) in the bookmark manager for turning the feature on/off. If you have a handful of sites you check every morning put the links in a folder and auto-tab it. One click on it will now open all of the links, each in a separate tab, replacing whatever tabs and pages you were looking at.
If you accidentally hit this auto-tab bookmark and lose everything you were working on (i.e. a weblog post) just hit the back button. Phew!