Is one ram card better than two?

     My wifes computer has two 128 meg ram cards , my computer has one 256 meg card . Is there any advantage in haveing two ram cards as opposed to one totaling the same amount of ram ?

Depends. If you're using a Pentium 4 or Athlon XP system, and your motherboard supports it (Intel 850 or later chipset for P4, VIA KT880 or later for Athlon XP), having two identical memory modules means it can use dual-channel mode, which allows data to be transferred twice as fast as single channel, resulting in a significant performance boost. If it's not a Pentium 4 and/or doesn't have dual-channel support on the motherboard, there will be no significant difference in performance.