I love Apptivate. It’s one of those specialized menu bar apps that does few things but does them well. It basically uses keyboard shortcuts to launch applications. What’s so useful to me is that it accepts single key shortcuts. This is one of the reasons why I use an Apple extended keyboard, to have the unassigned keys F13-F19 to launch my most used applications. This makes going through my day so much more pleasant. My setup:
I’m still looking for something for F17, but this covers the apps I use on the mac 90% of the time.