The long weekend gave me a chance to get started on my module. Currently it is called Finance::ChartHist, and basically produces graphs of a share price between two dates. The same as can be found on any financial website, such as Yahoo. I don't think there will be many other people that will find it useful, but it should be fun to build, and gives me a chance to get back into using perl.
Most of the grunt work is already provided by existing modules, namely Finance::QuoteHist which gets historical price information from various websites, and GD::Graph which produces pretty graphs. I got the basic outline of what I want done on the weekend, producing simple graphs, automatically formating the labels for the axis, etc. Most things are hardcoded at the moment, with the only options being the dates and ticker symbol currently, so I think my next step should be offering more options to format the graph.