While more Joomla! 1.5 templates are becoming available (For free templates visit http://joomla24.com) you may have a favourite Joomla! 1.0.x template you would like to use.

Some of the newer Joomla! 1.0 templates can work in Legacy mode on a Joomla! 1.5 web site but the best bet is probably to convert the template to a Joomla! 1.5 template.

Please note: You need to have some knowledge of working in code to be able to do it yourself, otherwise you may have a programmer friend who can do this for you.

Visit the official Joomla! wiki for a short tutorial on Upgrading a Joomla! 1.0.x template