The OSX version of Kensington's MouseWorks application provides a limited number of "scroll ring" speeds, and "Very fast" is really not very fast. Here's how to hack the com.kensington.mouseworks.plist file to provide a speed faster than what if offered. Open the plist using TextEdit. Look for this string:
<key>ScrollSpeed</key>
Directly beneath that line will be this line:
<integer>5</integer>
The number will be 1 through 5, depending on the setting you used in the MouseWorks System Preferences panel. If you're using this hack, the number will probably be 5, as that's the fastest Kensington permited you to set. That's the "very fast" setting. Change the number to a higher integer. I used 6, just to see what would happen and it seems to be fast enough for me. You might want 7 for the "Rocket" setting. Save the file. Log out and log back in. Done.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20041204171350592