By Unknown

Dropbox Wingpanel Icons

Dropbox is an essential service for many elementary users, but the default dropbox icons are a bit of an eyesore in elementary OS.
MrMagical has created a more consistent looking icon.
To install these icons, download, extract and and merge the following into the elementary icon theme.

To merge, you must open pantheon-files with root access by typing the following into slingshot:
gksudo pantheon-files
Enter your password, and navigate to:
Drag the status folder into the elementary icon folder. When prompted, select "Merge."
Finally, if the traditional style isn't your thing, take a look at Dikoo's cloud-inspired icons.
EDIT (4/26/2013): If you don't see the icon change, run the following command in the terminal:
sudo gtk-update-icon-cache /usr/share/icons/elementary/