Not all visitors to Canada are aware that taxes paid on a variety of items are reimbursable. Non-residents who paid federal goods and services tax (GST) on short-term accomodations or goods can get that money back by filing within one year of the date the tax was paid. Further, until November 1, 2001, visitors can also recover Quebec Sales Tax (TVQ or PST) paid on short-term accomodations. If included in a tour package, only one-half of the tax on accomodations is refundable. The form itself is easy to use.
There are some limitations. The total of purchases involved, before taxes, must exceed $200 CDN. Original receipts - not credit card slips - must accompany the filing. Each individual receipt must exceed $50 CDN before taxes. Unfortunately, taxes paid with restaurant expenses and admission tickets are not eligible.
Type "Canada visitor tax refund" into any internet search engine and you'll get a variety of pages back. Most are services which, for a small fee, will take your paperwork, process it, and return you a check in $US. I've used a couple based in Washington state in the past and found them reputable. You can also go to the Canada Customs and Revenue Agency at their website to get the form and cut out the middleman. US residents will even get a check in US currency, eliminating the inconvenience of curency conversion.
It doesn't make a big difference economically, but it's nice to get something back from the government - any government!