I use the library a LOT and probably visit it once a week to pick up, browse or return items. I use it mostly for books and DVDs, but those are really just the tip of the iceberg. The Ottawa Public Library offers family passes to the National Gallery of Canada and the Canadian Museum of Contemporary Photography, the Museum of Nature, Science & Tech, Civilization... all on loan for a week during which I can use the pass every day. I can even borrow a "Kill-a-Watt" meter to measure power consumption in my home or a pedometer to count my steps to health.
The library also hosts or provides meeting space for stuff like writing groups, the local Jane Austen Society chapter, homework clubs, conversation and friendship circles. And let us not forget the wide-ranging reference and information services for which libraries are known in the first place.
A bonus tidbit for the locals: Did you know that Ottawa still has an original Carnegie Library standing? According to Wikipedia, the Rosemount Branch opened its doors in 1919 and was the last Carnegie grant given in Canada. Lucky us!