It appears that the Google Keyword Suggestion Tool has gone offline from yesterday evening to this morning.
Several reports from DigitalPoint Forums have confirmed the issue with the keyword tool.
If you have not used the tool, you should give it a try. It has come a long way since Google first released the tool.
The short 8 hours of the tool being offline really seemed to worry many advertisers and Webmasters.
Forum discussion at DigitalPoint Forums.