Hootsuite was originally called "BrightKit", but the name was later changed due to it being too similar to another tool named "BrightKite".
Internally and not released to the public yet, HootSuite had it's creation on October 24th, 2008. With it's public launch in November 28th, 2008.
Initially the tool was created by two people: Beier Cai and Paul Donnelly. I was one of the people to first test it before the public launch, as Beier and I had been friends and colleagues since 2007 and because I was the one who first introduce Beier (and a number of others) to Twitter.