I've had my Macbook air for 3 years but never had to troubleshoot it before because nothing's ever gone wrong with it. It's running OSX 10.6 snow leopard.
There always used to be an icon in the dock that I could click to open up a list of all apps installed on the machine (basically like the windows start button). As far as I can remember it was just to the right of the dock resizer control. I don't know what it's called but I don't think it's launchpad because that seems to have been introduced in 10.7.
Anyway for some reason this has disappeared from the dock so the only way I can launch apps that aren't glued to the dock is by using finder.
I've tried looking in the applications folder for something called "launcher" but there's nothing there.