Does anyone know a way of determining the last known IP of a user on one's contact list that is currenty offline?

The background is this; my girlfriend's laptop was stolen a few days ago. I now see that Skype is reporting her as "last seen" yesterday morning. I would really like to know from which IP this login was made. It must have been someone using the stolen laptop doing this login (Skype starts and logs on automatically on her, now stolen, computer). If I am able to find out the IP I may give this information to the law enforcement authorities...

As far as I am aware the information you require would need to come from Skype - if it is required by law.
There isn't a way for a user to determine someone else's IP address.
Presumably you have alerted the Police.
They may have a 'fast track' method of obtaining the IP.
Good luck!
I hope you can safely recover it.
Please advise if you need any assistance in making Skype aware of the situation.

I sent you an e-mail if you did not get it send me a PM with the username - setup on that Laptop.

My mothers laptop got stolen just a few hours ago. The perpetrator hasn't logged on to Skype yet, but I suspect he might. Would it be possible for me to get his IP address if he logged on as well?

Sadly, once a laptop is stolen if it was not set up to provide a IP address to someone, it is very hard to get law enforcement to help locate it.

Here are some methods I created to that you can do to increase your chances of a laptop being returned:

http://www.dslreports.com/faq/laptop/Prote..._Odds_Of_Return

One in Ten Laptops are stolen

An IP address will only provide an area that might be using it. It will not pinpoint the exact location. I tried this with one other user and it is not possible to locate the culprit this way. Sorry. It will say the country in most cases. But if no calls were made from Skype then we will not even know that.