Recovering from 'the application finder can't be opened'

Every now and again I get an error when opening finder:

'the application finder can't be opened'

Whilst I am sure a restart would fix it, I normally don't want to restart as I am in the middle of something. The solution is to run the following in terminal:

/System/Library/CoreServices/Finder.app/Contents/MacOS/Finder &

(don't forget the &) If this continues to happen I should probably try and find the cause, more likely that I will just map the command to a bash alias though :).