1. Go to »www.411.ca and do a reverse lookup for the street you're thinking of moving to. You'll get a few names and phone numbers of people who live on that street.
2. Go to the availability checker on IGS's website and see what the results are for some of those phone numbers.
This will give you a reasonable idea of what level of DSL service is available, if any, in the area.
This method is not foolproof. In some instances, one resident could have 4 Megabit service, while a neighbour may not be able to get anything because there is no spare equipment available, or their line is poor, or routed to a different head end, etc.