The rubber band effect can be disabled to some extent using terminal commands as described in this article.
However, that doesn't turn it off in Safari. It seems the best option is to use a nonApple pointing device.
Many of the new UI animations in OS X are annoying, searching for "Mac OS turn off effect" in Google brings back many, many responses for different effects so clearly there are lots of people who want to turn them off.
One effect I do like though is inertia for scrolling. It makes scrolling much more pleasant. But as for rubberbanding, it's not for larger devices, leave it for iPods and phones.