Very cool capture!! You can upload the files into Dropbox.com. I believe you can create a free account, and have at least 1 gig of free storage.
There are many dark spots throughout the photo. I've had some like that which were dust spots. But yours could be just the splash from the rain. You can test it by taking a photo of a light colored wall and stopping the lens down to f16. Any dust spots should show up on the photo.