I need to connect a GPS unit to new laptop which has USB ports. Old laptop had a serial port.

I guess they do exist: Canada USB serial adapters, USB computer serial adapters at TigerDirect.ca (http://www.tigerdirect.ca/applications/category/category_slc.asp?CatId=464)

There are tons of adapters available Serial to usb

1 example: USB to Serial Adapter - SW-1301, $12.45 (http://sewelldirect.com/usbtoserial.asp)