Well yes, it is. Sometimes. I'm sitting in the lounge beside the Christmas tree with a laptop on my knee connecting through a wireless access point in the spare bedroom.
On the minus side, we have two access points (yes, two - but one is used as a bridge for certain functions) and in the past month BOTH power supplies have packed up and both access points needed their firmware reloading. You don't get those sort of problems with a length of CAT-5 cable.
Of course being the sad engineer type that I am whenever something electrical gets thrown out I always keep the power supply. So when I needed a 5 volt 1 amp supply with a 3.5 mm connector ...