Safari 4's Top Sites is a flashy, useful feature, but it's not exactly intuitive how to manually add a site to it.
As the Tech-Recipes blog points out, one of the easiest ways to bulk-add your links to Top Sites is to create links to each site on the desktop, either by dragging the URL from any browser's address bar or manually creating them with a right-click New/Shortcut action. Then simply launch Top Sites and drag your desktop bookmarks into the grid. You'll see the site thumbnail soon, but you won't see the delete/pin/update notifications while Safari is running this time. Launch Safari again, and all is well. I've found that another, semi-easy way is to simply type in the URL of a site into Safari's address bar while Top Sites is open, and don't hit enter or head to the site. Then just drag the URL you typed in down into the Top Sites grid, and you're good to go. Got an easier solution, or another Top Sites hack? Tell us about it in the comments.