The Ubuntu deb package available for download via the official Dropbox website requires Nautilus. But if you're using Xubuntu (Xfce), you'll probably want to use Dropbox with Thunar, the default file manager, instead of Nautilus.
So here's how to install Dropbox in Xubuntu/Xfce without Nautilus and get some basic Thunar integration (you won't get file emblems, but you'll get options to browse the file on the Dropbox website, get shareable link and view previous revisions, like in the screenshot above).
Install Dropbox and a Dropbox Thunar plugin in Xubuntu
1. Firstly, let's install Dropbox without the Nautilus dependency:
In Ubuntu Oneiric, Precise and Quantal, the "nautilus-dropbox" package available in the official repositories (it's not the same as the deb downloaded from the Dropbox website) doesn't depend on Nautilus, so you can install it on Xubuntu too:
sudo apt-get install nautilus-dropbox
That's it for Xubuntu Oneiric, Precise and Quantal users. Now simply open Dropbox from the menu (it's under Internet) and follow the setup wizard, then skip to step 2.
For those who are using an older Xubuntu version or another Linux distribution, you can manually install Dropbox without the Nautilus dependency using the commands below:
cd && wget -O - "http://www.dropbox.com/download?plat=lnx.x86" | tar xzf -
cd && wget -O - "http://www.dropbox.com/download?plat=lnx.x86_64" | tar xzf -
To start the Dropbox daemon (and the setup wizard if this is the first time you're installing Dropbox), use the following command in a terminal:
2. Install the Dropbox Thunar extension. Crunchbang provides thunar-dropbox deb packages that work with Xubuntu 12.04 - download the debs below:
I've tested the above packages with Xubuntu 12.04 and they work, but they may not work with other Xubuntu versions, so if you're not using Xubuntu 12.04, grab the Dropbox Thunar extension source from HERE (you'll have to compile it). Obviously, they also work if you're using Thunar in another desktop environment, like GNOME (Unity).
Arch Linux users can install thunar-dropbox from AUR.
Note: Dropbox needs to be running for the Thunar context menu items for Dropbox to show up.