Every day around 3:45 PM, a group of birds comes to our house. There's a vent outside (I don't know its purpose) that makes a happy little nesting ground for them, especially in this cold weather. When they arrive, they make a great deal of noise. Today, urged by Lisa, I made a recording of it. Take a listen (150kb mp3).
I made the recording with my homemade microphone and my minidisc recorder. Because the birds are on the other side of a wall, I had to turn the sensitivity up high, which resulted in a lot of noise—both from the cheap microphone, and from our neighbor's TV downstairs.
To get rid of the noise (how noisy was it? find out), I used Amadeus II, a sound editor for the mac. It has a bunch of features that are cool for people who work with sound a lot, but its noise reduction features really made my day today. Check it out--it's free for 14 days, then you pay $25 to register.