A blog at Cipherdyne describes a tool named Gootrude.

blog:
http://www.cipherdyne.org/blog/2008/06/trending-low-volume-google-searches-introducing-gootrude.html

Gootrude:
http://www.cipherdyne.org/gootrude/

They were dissatisfied with the inability to get data from Google Trends about low volume searches. They developed this tool that tracks Google's reported match count over time for submitted terms. It also provides graphs of the measured trends. As I understand this, Gootrude trends are trends of document references as reported from Google web searches, not trends of queries as reported by Google Trends.

The blog reports some sample terms and phrases that have been measured daily for about a year. I was surprised to see that these did not simply increase with time. The blog provides their analysis of this.

Currently the code for this open source project is available for download. There are plans for a public server in the future.