yes it is true - the wireless card in your machine will "see" any wireless connections in range...
However...
Where you are at any time might not have a wireless connection in range.
Any wireless connections your machine may see may be security protected and you will not have the security key to make a connection.
Other connections without a key will belong to somebody - you should have their permission to connect - otherwise it will be an illegal connection.
Hotels often charge guests for wireless connectivity - some public places have hot-spots for free public connection.
Enjoy your stay.
Peccavi, February 2011