In late 2006, early 2007 I worked on a site like TaskRabbit, but it was called Oddjobr.com (or oddjobr.net but I think I had both to be honest). I let the domain go (apparently it was picked up), but at the time I had a mostly working website up and running (it was a software lifecycle class project - with a team of just myself). It was a reverse auction though, bidding on jobs.
Are you sure these are clones? I didn't check em all out, but just throwing out that if I thought of this idea independently, it is likely others have too.
I kicked one of these around in 2007-ish as well - the idea by itself isn't incredibly unique. What's new is the level of focus and quality of execution. They may not be copying Task Rabbit exclusively, but it's no longer a space populated entirely with hobby projects.
Exec isn't so much a task rabbit clone, yes it's a similar concept to TaskRabbit but they've in my opinion improved the concept and TaskRabbit is far from dominant.
In Germany and the UK Milk.ly is quite big and has a much better looking Interface, that's why TaskRabbit is pushing for a London launch asap to compete.
Are you sure these are clones? I didn't check em all out, but just throwing out that if I thought of this idea independently, it is likely others have too.