How to setup Joomla on 1and1 servers (assuming you have ssh access).
1) Login to your 1and1 admin page and create a new MySQL database for your new Joomla website (this will take a few minutes so lets start it right away).
2) Download the latest .zip from http://joomla.org
3) FTP it up to your 1and1 home directory.
4) SSH to your 1and1 account.
5) Create the directory that will host your Joomla site and copy the Joomla zip file to it.
6) CD to the home directory and unzip the Joomla zip file.
7) Go to the 1and1 domain admin page and setup a domain or subdomain for your Joomla site and set the home directory to the directory you created in the previous step.
8 ) In a web browser, go to http://<your-domain>, and follow the prompts until you get to the ftp step.
9) For the ftp, select Yes and enter your ftp login and password. The home directory should be /<directory> with the name of the directory you created two steps back. Click the Advanced box and set the FTP Host to the domain name you setup in the prior step. Click Yes to save the ftp password. Click the Verify FTP Settings and if it fails, try the Autofind FTP Path option. Then, click Next
10) On the main configuration page, click "Install Sample Data", then click Next and follow the remaining steps.
11) Create a file in the home directory of your site called .htaccess with a single line: AddType x-mapp-php5 .php
Here's another take on setting up Joomla on 1and1 - http://sschill.wordpress.com/2010/01/12/installing-joomla-on-a-1and1-com-hosted-site-manually/