Is it possible to use the registration code twice? I mean that can i install it on my PC laptop and stationary Mac? PLEASE RESPOND !

You can use it up to five times concurrently.

I have used my license on as many as nine different machines.

I currently use it on two different laptops at the same time, and it's always been on at least these two.

You can have both of them logged in at the same time. I frequently have the "good" machine open and playing on it, and the little netbook connected and logged in (on the same id) and up dating as a slave.

You will, of course, have different galaxies on each machine, and different planets. None of the "galaxy" data transfers.

Any creatures you put on the server from one machine will migrate to your other machine, as well. But of course, if you make a creation on one machine and don't release if, it won't be on the other machine automatically.

You CAN copy your single creations from your C:\Documents and Settings\*** Your User Login***\My Documents\My Spore Creations file (and where ever mac hides it) to a thumb drive and put them in the corresponding folder on the other machine.

DON'T overlay the whole directory! Just move the individual creatures. I do this with some creations I don't want to share, except with friend and family. You do lose the lineage this way.

Depending on when you connect to the server, the "creation" times on the two machines for creatures won't line up exactly. It's better to do it frequently, so they stay "in sync".

MisterHaan also runs on two or more machines at the same time. I know there are others, but you could pm either him or me if you have questions.

http://www.spore.com/view/myspore/misterhaan
http://www.spore.com/view/myspore/ashkelon

This article from the FAQ could also help
http://forum.spore.com/jforum/posts/list/20627.page#439637

I also lied a little about "losing" the lineage. You won't really "lose" it, per se, but you can get it really hosed up. Like two of you can publish identical creatures and both be the "original" creator -- stuff like that. But if you're using the same id on both machines, that really doesn't matter.