Check in for your flights here.  Be sure to have your confirmation number and the name of the passengers.

Air Canada:

http://www.aircanada.com/en/travelinfo/traveller/checkin/

Air Jamaica Airlines:

http://www.airjamaica.com/

AirTran Airways:

http://ebyepass.airtran.com/findreservation.aspx

Alaska Airlines:

https://webselfservice.alaskaair.com/checkinweb/(1znils5504fqad4540odf455)/default.aspx?language=

American Airlines:

http://www.aa.com/content/urls/checkin.jhtml?anchorLocation=DirectURL&title=checkin

British Airways:

http://www.britishairways.com/travel/home/public/en_us?countrycode=US

Continental Airlines:

http://www.continental.com/web/en-US/content/help/onlinecheckin.aspx

Delta/Northwest Airlines:

https://www.delta.com/oci/servlet/OCIServlet?cmd=getOciLanding

Frontier Airlines:

https://www.frontierairlines.com/frontier/plan-book/online-check-in.do;jsessionid=ca983971af6dc8ffffffff91464bc1a128895

Hawaiian Airlines:

https://apps.hawaiianair.com/checkin/

jet Blue:

https://www.jetblue.com/manageflights/checkin/

Lufthansa Airlines:

http://www.lufthansa.com/online/portal/lh/us/info_and_services/checkin/web_checkin?nodeid=1699745&l=en&cid=1000390

Southwest Airlines:

http://www.southwest.com/content/travel_center/retrieveCheckinDoc.html

United Airlines:

http://www.united.com/page/article/0,6722,50446,00.html?jumpLink=%2Fcheckin

US Airways:

http://www.usairways.com/awa/webcheckin/default.aspx

Virgin Atlantic Airways:

https://www.virgin-atlantic.com/en/us/manageyourflights/diycheckin/index.jsp