@Nathan Lichtman
Using OPM can be a valuable tool in your real estate toolkit but it's important to remember it's still debt. Just because you have less money into the investment doesn't mean you're free from risk. It's always important to make sure you're not over leveraged in any one investment property and to have a firm grasp on the property's I&E. I am a proponent of using OPM for the right situation (read my profile) and I arrange OPM financing only for certain clients.
Hard money lenders (MICs in Canada) are by far the most common type of OPM finance. MICs provide a loan up to a portion of the property's value, oftentimes including things like renovation costs. These lenders offer short terms such as a year or less - it allows you to exit and roll over to the A side without penalty. You can also secure financing outside of a formal hard money loan, for example from a friend or family member, which usually will offer a lower interest rate. Right now mortgages from "A" lenders are so cheap and even B lenders are offering low rates of 5% for a 1st mortgage.
Your question, "If you had 100k in Canada and a job that produces 40k/yr, what would you do over the next 4 years in real-estate?" I'd have a game plan for financing for the next, next, next... property.