Alert me when a certain app/process isn't running
I ended up writing a simple applescript and creating a cronjob to run it every 10 minutes.

When Last.fm is not running, this launches it.  when it is running, it does nothing.

AppleScript:

tell application "Last.fm" to run


Cronjob

*/10 * * * * osascript /Users/Jacob/Documents/AppleScripts/LastFMRunning.scpt