I've been trying to become better at giving donations to charity, and using Remember the milk I have found a good way to do so. I used Things to do this earlier, but I didn't find a good way to do it, but with Remember the milk everything works nicely.

Without trying to brag or anything, I have started giving an amount each month, but I started thinking if I could give small amounts on the basis of what I do daily.

Each time I use my car, I want to give money to a fund trying to preserve the rain forest. When I go shopping I want to give money to the Red Cross or some organization helping the poor.

So using repeating tasks, I have set up daily amounts that I must give each time a do something. In combination with places, I have created "car, shopping mall, grocery store" as places, and each time before I go there I check if there is something I must buy, and I also see that I have to give a donation.
Since I don't go to the mall every day, I can have 10 donations in my shopping mall list, but I only check one each time I go. If someone have a better way to do this, please let me know!

I then have a task which repeat at the end of each month, which tells me to pay out the amount. I then I have created smart lists for each cause I'm giving to:

status:completed and location:Car

If I use my car a lot, I give more money. If I use it less, it's better for the environment!