I would recommend QuickLaunch program, available from repos. It's quite flexible - configuring it correctly (from GUI in control panel), you may set it up to start on camera launch, allowing you to select one of four defines applications.

I do *not* recommend camera lesn cover launcher. It uses ~6Mb of RAM all the time for no reason, and it's bugged. I got rid of it ages ago, but gave another chance, after noticing sixwheeledbeast is using it. Well, nothing changed - memory waste as it was, and after trying to set it up, it got hopelessly stuck into allowing only *one* program to be selected from pop-up (no ammount of reboots/killing helped). Also, ocassionaly it spawns few clones of own process. Got rid of it, and returned to quicklaunch with pleasure.

/Estel