Square is a new device available currently, only in the US. But watch this idea grow because soon someone will provide this service for Canadians. Square is a device that lets you use your smart phone (or iPad or other wireless device) to use customer credit cards for sales. This has long been a problem for many artists, but soon, I suspect, we will have a solution like Square in Canada.
Square (the device) is free, but you pay a per-transaction fee.