Here is a list of action items from Tim Flannery's web site (author of The Weather Makers). After some items, I've provided links to local (mostly Ontario) resources and information.
(Action = Impact)
1. Change to accredited Green Power option = Eliminate household emissions from electricity
It's easy to do this in Ontario:
Green Tags Ontario
Oakville Hydro's Green Power program
More information is available at Electricity Choices
2. Install energy-efficient hot water system = Up to 30% reductions in household emissions
You can install a tankless (on-demand) gas system, or a solar (thermal) system, or both!
OZZ Corporation offers high-efficient tankless hot water heaters. You can buy or rent (according to their web site)
I've also noticed them for sale at the Home Depot.
Lots of places that sell solar systems are listed on the Electricity Choices web site.
BONUS: The Ontario government is offering residential consumers a full sales tax rebate on the purchase of solar energy systems and components up to November 26, 2007.
Another energy-saving idea: Install a heat-recovery unit on your drain to recover some of the energy wasted by showers, etc.
3. Install solar panels = Eliminate household emissions from electricity
While this is a great idea, it can be really expensive. (I wouldn't necessarily recommend doing this until you've made your household as efficient as possible first.) However, with the new offering from the Ontario government it has become somewhat more cost-effective. Some people in Toronto are trying to implement this in their neighborhood.
If you want to do this on your own, Electricity Choices has a list of suppliers.
4. Use energy-efficient whitegoods = Up to 50% reduction in household emissions from electricity
When replacing your old appliances, be sure to look for the Energy Star logo!
5. Use triple-A rated shower-head = Up to 12% reduction in household emissions
These are available at any hardware store. Here's some information from HydroOne.
6. Use energy-efficient light globes = Up to 10% reduction in household emissions
Again, these are available almost everywhere. The Ontario government send some coupons for $5 off on these earlier this year.
7. Check fuel efficiency of next car = Up to 70% reduction in transport emissions
Ontario offers up to $2000 rebate on the PST when you purchase a hybrid vehicle.
8. Walk, cycle or take public transport = Can reduce transport emissions
Taking the bus, train, or your bike can be lots of fun. We've started to take our weekly trip to the grocery store by bicycle (when the weather permits). It's fun, and we get some exercise!
9. Calculate carbon footprint = Can eliminate transport & household emissions
Some places online that you can do this:
Although the Government of Canada has taken down its climate change web site, their GHG calculator is still available (for now!). Visit while you can.
There is also CarbonFootprint.com, Al Gore's version, and one from the World Resources Institute.
There are many more out there if you Google 'carbon footprint'. Take your pick.
Of course, then you need to decide what to do with the information. For example, maybe you want to offset your emissions. Lots of choices there too. The David Suzuki Foundation has a list of vendors, as well as lots of info.
10. Suggest a workplace audit = Up to 30% reduction in emissions
This site is from Australia, but the ideas should work here too.
11. Write to a politician about climate change = Can change the world
OK - I've tried this, and I don't think I've changed Rona's mind yet. But maybe if we all join in? It can't hurt, anyway! See this post for contact information for your federal politicians.
And don't forget your provincial and municipal politicians - especially with municipal elections coming up soon. We emit GHGs at all levels of government!
Edited to addd: Check out this post for more links to information in other provinces.