Due to the upcoming release of Dropbox 0.8 and its ability to support Application Indicators (and custom icons), many people have been creating icons for it to blend into the Ubuntu-Mono icon set.
However I have yet to find a set that is made in the Elementary style, so I decided to do it myself (the initial idea is based on these icons)
Below is a link to the GNOME-Look page where you can download them. Once the ZIP file has downloaded, you need to extract the files into ~/.dropbox-dist/icons
What do you think?