The answer is simple, but not automated. Hacking the URL is the only way to do it.
First, you have to get yourself a hackable URL. Do a search for whatever you want, and scroll down to the bottom and click on any of the result pages in the Google results navigation (you know, the one that looks like this "GOOOOOOOOOOOOOOOOOOOOGLE"). The resultant page has a slightly different URL than the page you were just on - a URL that you can mess with fairly easily.
In this slightly different URL, you should find a key that says "start=x" where X is a positive whole number. This number will always be less than the number of non-similar entries on a given subject and (I would guess) be equally divisible by the number of entries per page that you have chosen to display - the default is ten.
Changing this number in your browser address bar will allow you to "quickly" jump to specific results pages. For instance, changing it to 100 in a result set of 200 entries, will get you halfway into the results...(yes, obviously ;)
The trick lies in guessing where the last page is. Bret noted that there were 950,000+ entries for ICANN, so presumably changing this number to 949,990 would do the trick, but natch - that just brings up an empty result set.
I decided to see if this was just a big number problem and dumped 999 in. Again, nothing. Scaling back to 500 got me something again - so I split the difference and went up to 750. No results again. I dropped back to 700, got results and then decided to increment by 10 until nothing.
In this case, the magic number is 720 - there are 727 unique entries in the GoogleDB for "ICANN" - the last of which being the Webopedia "Who's Who" bio's that start with "C" - includes Vint Cerf, ICANN's current chairman.
Personally, I can't wait to see what name the community gives to this particular activity. I vote for "Googlediving" - it needs a better last page.