If you're using the Joomla templates from JoomlArt they have quickstart versions of the templates which allow you to install your own copy of their demo version on your own Joomla server. If you're not familiar with JoomlArt, check out their example templates here.
To view much of the information that follows and to download the JoomlArt templates, you'll need to purchase a subscription with JoomlArt. A description of the subscriptions options can be found here. I purchased the Standard Membership for $59/year.
User guides and instructions on downloading and installing the templates can be found in the JoomlArt forum for the template you're working with.
Quickstart Install on 1&1
The Quickstart zip file for each template can be found with the rest of the downloads for that template (go to the main JoomlArt Templates Page, select the template you're interested and then the Download link on that page). The install instructions for the JoomlArt quickstarts can be found here.
Unforunately, there's a problem with the format of the quickstart zip files that does not allow you to un-zip them on linux servers. Here are the steps I used to install the quickstart template:
1) Create a home directory on 1&1 for your quickstart JoomlArt site. You won't need to install the standard Joomla bits from joomla.org. Just leave the directory empty. However, you will need to do the 1&1 setup steps described below - create the domain and a MySQL database.
2) Download the quickstart template to your PC. Note that JoomlArt quickstart templates are contained in a "quickstart" subdirectory inside of the template zip file that you download from their website. Within the quickstat subdirectory is another zip file (zip within a zip) that contains the quickstat files.
3) Un-zip the quickstart zip file to it's own directory and make sure you maintain the folder structure during the un-zip.
3) Use FileZilla or another ftp program to copy the entire un-zipped directory structure to your Joomla site's home directory.