Arg, I did not manage to count birds over the last weekend! Cornell Lab of Ornithology hosts the annual backyard bird count (and I urge you to register and do it next year!). Every winter citizen scientists like you and me can count birds for any period of 15 minutes over 3 day span, and then log the data in the website that Cornell maintains.
I've been a part of bird census counts for over 10 years via my local Audubon chapter so get in my citizen scientist kudos otherwise, but I fully intend to make more of this next year. Citizen scientist counts are invaluable for bird census data regarding bird populations, climate change, and human/bird adaptations.