Playstation network question?

May be...

if i connect my ps3 to a laptop with an ethernet can i always unplug it an plug it back in cuz its my sisters laptop plz HELP!

yeah my friend does that from his ps3 to his mac all the time. It should be perfectly fine. So don't worry about it man.

Well...I'm not exactly sure. I've disconnected mine from a wireless signal and connected it back when I moved it from place to place. So I don't see why it won't work. I say just take out the chord and find out.