As to the "usefulness" of such knives.... Bowies are purpose-built fighting weapons intended to be heavy enough and properly shaped for slashing, yet still allow thrusting.
 
The large guard (often built as "lugged" for trapping another blade) is a clue.... renders the blade rather awkward for more domestic chores.
Most all contemporary "fighting" or "tactical" knives are either a variation of the Bowie design or are straightforward stilleto-thrusting designs.
 
A big one would make a passable machete, but that's likely abuse.   The cheap Pakistani-made models make good throwing knives when you strip off all the hardware.  Or you can just throw it till it all falls off....

What's batonning ?

Quote from kuggur slingdog on May 7^th, 2011, 1:33pm:

 
By this criterion, you might ask "What good is a sharp longsword?" or "what good is a sling?" Ultimately a tool is designed to do a job of work. It is possible to do courses to learn to fight with a bowie knife as that was what it was used for as well as being a general purpose cutting/thrusting weapon, much like the modern machete. Such courses can be even more fun if you learn to use the bowie in one hand and a tomahawk in the other! Obviously you'd use a blunt for training but you could try practice cutting with a sharp version on tatami or pool noodles or water bottles. As stated above there are also incorrect ways to use such a knife but you can still have fun with it.

maybe for roughing out wood shapes? i used a cleaver for my bow, and i could cut out the shape in 30 minutes or so, hacking out the shape, then using a smaller knife to carve closer in. the bowie knife is a little thicker and not as wide, but it might work.

I've always preferred a large knife.  I can't explain it, and no, it doesn't make up for an inadequacy elsewhere, kuggur.    I've just always preferred the feel of a bigger blade.  I can't be alone in that they make so darned many of them.

Around town, like when dog walking, you just can't carry a big blade.  The cops would undoubtly frown on it.  When camping or fishing, however, I always carry a big survival knife.  I think that the blade is 9".  I just like the feel better than my smaller knives I guess.

When the knife becomes big enough one may need a small knife beside it for small work and the weight and bulk may compare to a small axe (hatchet/tomahawk/whatewer) which for many tasks often performs better than a big knife.
Then it comes down to personal needs and preferances.
 
Myself I have far too often been out there with a small and big knife, and an axe .  And then the big knife is not used a lot.  
 
Fortunately I got some light but very practical and useful 8 and 9" Same knives for when I insist on carry a big knife .
 
I can therefore leave the big and heavy knives at home when the urge comes.  
 
As long as bear defence is not an issue a small folding saw usually outperforms any big knife or an axe anyway for camping use .