Length of speaker cables

If you cut them in half, you will have half the inductance, resistance and capacitance. However, I doubt whether the difference would be audible to you. However, if you are running single wires and use the opportunity to double up and biwire, then you might hear something. Also, if you use the opportunity to upgrade your speaker cables since shorter cables typically cost less, that may also provide an audible improvement as discussed by @millercarbon .  I typically use 1M long speaker cables with my monoblocks.

My suggestion for cables would be Canare 4s11. It's inexpensive and very good wire. 

Just to be clear steven0713 when saying you will definitely hear worthwhile improvement with quality cable I mean quality cable, not that 4s11 stuff. You can spend a lot and still have crap if you're not careful. 

I use Audioquest GO-4's for my Vandy Treo's and Ayre monoblocks.
The length is 6 feet.
My dealer, John Rutan, swears by short speaker lengths (As does Ralph Karsten (atmasphere). Anything longer introduces/enhances cable artifacts.
I don't know what your system is besides the AQ cables, but if you have 'good' equipment, and some disposable income, I would suggest buying a pair of AQ William Tell cables.
I heard them at Audioconnection and the difference between the GO-4 and William Tell was amazing- and I am not a cable nut. 
They were truly cleaner/clearer. Even the bass was enhanced.
Like I said, I am not a cable enthusiast, but those cables were absolutely amazing. Yes, not inexpensive, but, in my mind, worth the cost.
Bob

millercarbon 

Just to be clear steven0713 when saying you will definitely hear worthwhile improvement with quality cable I mean quality cable, not that 4s11 stuff. You can spend a lot and still have crap if you're not careful.

The Canare 4s11 is worth trying out.  The poster quoted above is known to be a fanboy of certain brands (only those he owns) and has difficutly seeing beyond them.  When he mentions spending a lot, that is true, if you consider spending $81 dollars for a pair of terminated 6' Canare 4s11 from Blue Jeans Cable a lot.