Couch surfing means spending the night on the couch, spare bed or floor of an acquaintance in lieu of a hotel. In Ottawa as anywhere you generally get as much as you give, and there are many ways to arrange it. Some people arrange free stays with strangers across the world using the San Francisco-based couchsurfing.org—a somewhat disingenuous moniker since the company switched from a member-supported, not-for-profit company to a for-profit company in 2011. This move disillusioned many original backers, who have also criticized the company for running on an invasive Facebook-like business model.
Of course one can always crash with friends without subscribing to a data-mining behemoth. Offering space in your home to a trusted person provides the benefits of company and reciprocity.