There's a lovely article in the NYTimes about planting native plants to help bird populations. This is an angle I'd not thought of before. Of course, we know that invasive species aren't good, and we try to get rid of them. But why are they not good? Well, because the invasives cannot support insect larvae.
Wait a sec, you say? We want insects? I don't want more insects! Okay, maybe we don't want more bugs flying around. But a whole lot of birds eat bugs, and we like birds, right? Also, remember that butterflies are big, flying insects (and lovely ones at that).
Take home message: plant native plants in your yard (and that's plants more or less native to your area). They'll be a breeding ground for local insects, which will bring birds that feed on those insects. Then, sit back and enjoy the fact that you are helping nature, reducing your footprint (less water use for natives), and being a fabulous citizen.