From the Des Moines Register:
http://www.desmoinesregister.com/apps/pbcs.dll/article?AID=/20061126/NEWS09/611260338/1056---
"The Iowa Republican Party has selected Aug. 11, 2007, as the date for the Ames straw poll - a signature event for GOP presidential candidates running in the state's leadoff nominating caucuses.
The event, a party fundraiser that includes an early showing of candidate support, is planned for Iowa State University's Hilton Coliseum, party aides said.
Several Republicans are weighing campaigns for president in 2008, although none has declared his or her candidacy. The straw poll is a nationally publicized event, noteworthy as the first measure of candidate strength in Iowa.
In August 1999, a record 25,000 Republicans turned out for the straw poll, which was won by George W. Bush, then the governor of Texas."
----
When the top candidates decide to contest the IA straw poll (as they usually do), it tends to become an important early show of strength for the winners, even though it has no more bearing on delegate selection than a telephone survey, and is an entirely media-driven event. In 1999, I believe it helped drive a couple of the weaker candidates out of the race.
