If you're a Google Analytics super-user-junkie, you'll sometimes run into problems exporting large keyword lists for your own entertainment or actual client work. There's a quick and slightly dirty solution to this (thanks to Matthew Attwell for the tip):
Firstly, go to the bottom of the Traffic Sources > Keywords list:
You'll likely have more keywords than the "allowed" 500 - look at the end of the URL:
Where it says &trows=500, simply change it to 50000:
Don't expect the visual result (i.e. more than 500 keyword rows) to change. Instead, export the document to a .CSV file:
Unfortunately, 50,000 rows is the maximum that a comma separated value sheet will allow - once you've changed the limit, you'll be able to export a relatively full keyword list.
Update (23/06/09): Rob mentioned in a comment below that changing the trows parameter didn't work for him. If you're having problems getting it to change, set the limit parameter to 50000 instead of trows.