Currently I'm working on a village planner for Travian. It was inspired by the village planner at http://www.ebav.co.uk/travian/, but I was missing a possibility to save and reference my village. So the main feature was saving the village to a bookmark. This is done by the URL parameter “a”. The parameter contains one character per field and the character defines which building to show. You can have a look at the current version at http://travian.andunix.net/village-planner/index.html.
Here are some features which are still missing: