Combining some findings from a recent hint and on Apple's forums, I've finally found a way to disable the annoying rubber-band scrolling in most applications. All the credit goes to those guys as they did the initial investigation.
It works in applications like:
It should work after you relaunch your applications.
defaults write -g NSScrollViewRubberbanding -int 0
[kirkmc adds: Works as described. I haven't tested many apps, so feel free to post which ones work and which don't in the comments.]
defaults delete -g NSScrollViewRubberbanding
Mac OS X Hints