Centrino is the name for intel's bundle including a pentium m cpu, a certain bridge chipset, and their wireless card so hotspots aren't just for them. Hotspots are just open wireless access points. You might find them in libraries, schools, coffee shops, meeting rooms, etc. Usually you just connect and go. A word of warning though, many people have poorly configured access points too and let everyone on their network without them knowing it. Connecting to a network you don't have permission to use would be illegal, so you should make sure the owner wants you to use their bandwidth really. Have fun, wireless is great stuff.