I like how it is possible to drag links from web pages to the tab bar in Safari to create new tabs, or to change an existing one, and it is something I use frequently. However, what has bothered me with Safari in Tiger is that if the current view is focused somewhere over the middle of the web page, the page auto-scrolls upward as the link is dragged over the threshold at the top of the content portion of the window. One way to modify this behaviour is to set a delay so that the auto-scroll doesn't kick in right away. For example, quit Safari if it is running, launch Terminal (in /Applicatons -> Utilities), and enter this command:
defaults write com.apple.safari NSDraggingAutoscrollDelay -int 3
This sets the delay to three seconds, although as desired, any positive integer could be substituted in place of the 3. Three seconds works for me to prevent unintentional scrolling, while retaining the ability to scroll if required -- something that happens rarely enough for me to justify a three-second wait.
defaults delete com.apple.safari NSDraggingAutoscrollDelay
[robg adds: This command should work in any other Cocoa app that has autoscrolling, such as other browsers based on Apple's WebKit. You'll just need to change the com.apple.safari bit to reflect the app you wish to modify.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20060824084741428