Easy and simple:
1. get source for Dropbox

https://www.dropbox.com/downloading?os=lnx

2. extract it tar -xvf nautilus-dropbox-xxxxx.tar.bz2
3. cd into extracted folder
4. try to ./configure it will fail with error about libnautilus-extension >= 2.16.0
5. make some magic sudo apt-get install libnautilus-extension-dev
6. try again ./configure it failed for me saying cant find docutils
7. sudo aptitude install python-docutils
8. ./configure
9. make
10. sudo make install

After 10 steps its not so easy and simple.
I hate linux just for making everything not easy. Some times it feels they are doing it on purpose.