Import Tabs from Other Browsers
When I made a visit to MacTips, I stumbled upon the article entitled Drag Tabs Between 2 Browsers. To my disappointment, after some trials, I still cannot drag my Safari tab into other browsers but I succeed to do it oppositely from other browsers to Safari.
However, for shortcuts addict like me, I prefer to use combination of keystrokes Command-L (jump to url bar) ▸ Command-C (copy the link) ▸ Command-Tab (switch application window) ▸ Command-V (paste the link).
Migrate to New Window
When you drag one of your Safari tab vertically down from the tab bar, you will see a mini-display of it. Drop it out of the tab bar and you will get new window of it. Similarly, you also can drag from new window and drop to the tab bar of different window to get the effect of merging both windows.
Rearrange Tab Order
If you drag one of your tabs and move it around, either left or right, the tab next to it will automatically save the space for this tab, which you dragged, by dancing around. This really comes in handy when you want to rearrange your tab.