Install prerequisites

sudo apt-get install automake autoconf libtool subversion-tools help2man build-essential erlang libicu38 libicu-dev libreadline5-dev checkinstall libmozjs-dev libcurl3-dev

Download and unpack latest build

wget http://build.couchdb.org/apache-couchdb-latest.tar.gz
tar -xzvf apache-couchdb-latest.tar.gz
cd apac... tab

Configure and install

./configure
make && sudo make install 

Create user couchdb

sudo adduser couchdb
sudo mkdir -p /usr/local/var/lib/couchdb
sudo chown -R couchdb /usr/local/var/lib/couchdb
sudo mkdir -p /usr/local/var/log/couchdb
sudo chown -R couchdb /usr/local/var/log/couchdb
sudo mkdir -p /usr/local/var/run
sudo chown -R couchdb /usr/local/var/run

Copy couchdb init script to global so that it gets started on server startup

sudo cp /usr/local/etc/init.d/couchdb /etc/init.d/
sudo update-rc.d couchdb defaults
sudo /etc/init.d/couchdb start

Or start manually each time you want to use CouchDB

sudo /usr/local/etc/init.d/couchdb start

Open http://localhost:5984/_utils/index.html in Firefox

Based on this tutorial: http://www.chetanmittal.com/2008/6/15/install-couchdb-on-ubuntu-hardy-heron-8-04