Why are jim beam bottles flat sided?!

Best Answer - Chosen by Voters

It's their trade mark....

I don't know where Tom got his answer about them being taxed higher. I see nothing about that anywhere. Here is a chart that shows taxes for liquor by state and type. It talks about it being taxed by the gallon, not the container it comes in:
http://www.taxfoundation.org/publication…

Here is another detailed chart on this subject:
http://www.taxadmin.org/fta/rate/liquor.…

There are surely many advantages to the design. And that style has been used at least since 1982, but I suspect much longer:
http://cgi.ebay.com/Jim-Beam-5-Unopened-…

The best answer I see here on this list of answers so far is the packing convenience. You don't need a cardboard insert. However, it could also just be a bottle style that is unlike any other styles so people recognize the bottle without even seeing the label. Coca Cola does that with their oddly shaped glass bottles (and now 2 liter bottles too). It's a brand recognition thing I would suspect.

So that they don't qualify for the "handle" tax

Liquor bottles with a handle, whether sticking out of the bottle or blown into the body, are taxed at a higher rate than bottles without handles

It's a safety feature. So that if you knock the bottle over you don't hurt yourself chasing after it as it won't roll away

They are flat-sided so that the low-lifes who drink that swill can hold the bottle without dropping it.

So they can be stacked in boxes or on shelves without needing cardboard inserts or racks