Have you come across sometimes the need to display the size of a document and document's type next to the link targeting it ? With this additional information, it can help your visitor/user to differentiate an 'attachment' link from a normal web link, whilst also giving them to consider the time needed to wait to either download or view the resulting content.
Vivociti AddSize is a plugin that will automatically add size and file type information into files which you have linked to from your articles. It makes use of addSizes script developed by Natalie D and json-head by Simon Willison, a Google App Engine application. I encourage you to visit their website for live demo.
Download Vivociti AddSize Plugin for Joomla 1.0.x and Joomla 1.5.x here (unzip first before start to install)