joomla 1.5 pagenavigation module needed (urgent)

in a custom joomla 1.5 template i'd like to show a link to the previous/next content item in the same category on some custom position outside the content area. that's why i cannot use the default [login to view URL] plugin, but basically i'd need the same functionality. i think what i need can be done with a module, but any solution that works would be ok for me, as long as it gives me a linkt to the previous and the next content item in the same category in joomla 1.5. no title for the link is needed as i will use ">>" and "<<" for those links. PLEASE NOTE: i CANNOT give you ftp access to the server/site - the solution would have to be built on some other server, i can send you the template and any file from the server, but would have to upload your files to test on my own ...