Killer photo - and that tree does make the image, like that guy said.
For finding out what you shot try http://nova.astrometry.net/upload
- this is pretty much the only service I'd consider subscribing to if it wasn't free
You upload your photo of the sky and in 2 minutes or so it gives you a wealth of info: apart from identifying stars and objects in your frame, it tells you your field of view, your sampling (arcsec / pixel), the exact orientation, etc. The object database is huge, and will even indicate tiny, fuzzy galaxies one may mistake for stars. That being said, Davenn did a fine job, cause all that black/city lights would have messed with their algorithms - works best with images of stars only.
Concerning noise - yeah it's noisy but so what. People pay for software like Photoshop so they can actually *add* noise to their photos. Pixel-porn is funny and should be left where it belongs: on übergeek forums for tech reviews. After spending hours in total darkness, freezing cold and twisting your spine to shoot some faraway galaxy, believe me, you won't care much about noise as long as it doesn't prevent you from seeing what you actually shot.
Careful with shooting the sky though - you'll start neglecting your loved ones, spend all your cash, you'll show up late for work with a Picasso-face, start worrying about things none will understand... much like heroin if you think about it 