Bradley,
 
That's exactly why I tune DOWN a half step - so I have the Bb, Eb, Ab, Db, and Gb open strings! Though it really started when I was playing only a four string and I never had the Eb that I needed. Since I still play 4, 5, and 6 string basses, it's easier to keep them all tuned the same way, even though it's really only the 4 that needs the extra 1/2 step.
 
That's just what works for me of course...
 
Loch