Don't know where you're at, but TJ is right; you may not need chains. I carry a set of Z chains but have never had to use them.
http://www.scc-chain.com/Traction%20Pages/Trac_SZLT.htmlCalifornia has R1, R2 and R3 chain restrictions.
R1 - Chains required, vehicles with snow tires (M+S on side counts) okay.
R2 - Chains required, 4wd with snow tires okay - carry chains.
R3 - Chains required on everything (you really have no business being out anyway).
As far as carrying chains, I once was pulled over with my old 4x4 and only had to show I had chains. I did have them but they were ones I found discarded in a parking lot and they would not have fit!
I prefer the cable chains as it isn't as likely to tear up your wheel wells.