Most airlines now offer "paperless" ticketing, especially when using various airline, travel agent, or travel provider websites for online reservations. Always keep track of your reservation's confirmation number, which you will need along with appropraite ID to check in at the airport.
Typically the airlines serving vacation tour operators (ie Air Transat, Skyservice) do not (yet) allow web check-in
Most of the major Canadian and US airlines now offer Web Check-In (see the list below). You can go online (typically 24 hours before a flight) from your home, office, or any Internet access point to check-in for your flight and print your boarding pass before you leave for the airport.
When you arrive at the airport, most airlines have baggage drop areas for those using the Web Check-In, which allow you to bypass the regular check-in/baggage drop line and save time.
Not all of the above airlines serve all airports covered by FoundLocally.com communities, but the full list is provided to help those passengers connecting to other flights at other airports. (If you are aware of other web check-in sites we should add to this list, please provide us Feedback.)
To further reduce airport line-ups for experienced travellers (and airline labour costs) many airlines offer self-service check-in kiosks. These are located in the airport, as well as in some downtown (and airport-area hotel lobby) locations.