In the PS3 it is the smallest size that came with WiFi
yes it has both WiFi and ethernet connection and can play on the PlayStation network just like every PS3.
ps3 80 gb.
ofcouse!
no
it cost $400.
Yes - the only differences between it and the 40GB version is the extra hard-drive space, and the fact that they generally come with the Dualshock 3, with built-in rumble.
More memory, that's all.
No it can not
Yes.
40 gigabytes
The 40GB system has not been new for some time, see timeline in related link.